Statistics Questions

The table below shows the average weekly wages in dollars for state government employees and federal government employees for 10 years Construct and interpret a 90 prediction interval for the average weekly wages of federal government employees when the average KE weekly wages of state government employees is 916 The equation of the regression line is y 1 433x 31 862 Wages state x 719 1 013 772 1 035 798 1 108 814 1 130 837 1 194 Wages federal y 868 1 247 922 1 265 940 1 304 950 1 341 and S 986 1 380 D Construct and interpret a 90 prediction interval for the average weekly wages of federal government employees when the average weekly wages of state government employees is 916 Select the correct choice below and fill in the answer boxes to complete your choice Round to the nearest cent as needed OA We can be 90 confident that when the average weekly wages of state government employees is 916 the average weekly wages of federal government employees will be between S OB There is a 90 chance that the predicted average weekly wages of federal government employees is between and S given a state average weekly wage of 916

K Calculate the coefficient of determination Use the value of the linear correlation coefficient to calculate the coefficient of determination What does this tell you about the explained variation of the data about the regression line About the unexplained variation r 0 951 Round to three decimal places as needed What does this tell you about the explained variation of the data about the regression line Question 11 of 16 of the variation can be explained by the regression line Round to one decimal place as needed About the unexplained variation of the variation is unexplained and is due to other factors or to sampling error Round to one decimal place as needed This quiz 16 point s possible This question 1 point s possible

K Given a set of data and a corresponding regression line describe all values of x that provide meaningful predictions for y OA Prediction values are meaningful for all x values that are realistic in the context of the original data set OB Prediction values are meaningful only for x values that are not included in the original data set OC Prediction values are meaningful only for x values in or close to the range of the original data 75

K What is a residual Explain when a residual is positive negative and zero GILB OA A residual is the difference between the observed y value of a data point and the predicted y value on a regression line for the x coordinate of the data point A residual is positive when the point is above the line negative when it is below the line and zero when the observed y value equals the predicted y value OB A residual is the difference between the observed y value of a data point and the predicted y value on a regression line for the x coordinate of the data point A residual is positive when the point is below the line negative when it is above the line and zero when the observed y value equals the predicted y value OC A residual is the sum of the observed y value of a data point and the predicted y value on a regression line for the x coordinate of the data point A residual is positive when the point is above the line negative when it is below the line and zero when the observed y value equals the predicted y value OD A residual is the sum of the observed y value of a data point and the predicted y value on a regression line for the x coordinate of the data point A residual is positive when the point is below the line negative when it is above the line and zero when the observed y value equals the predicted y value

on and Regression Quiz The table shows the amounts of crude oil in thousands of barrels per day produced by a certain country and the amounts of crude oil in thousands of barrels per day imported by the same country for seven years The equation of the regression line is y 1 222x 16 408 72 Complete parts a and b below Produced x Imported y a Find the coefficient of determination and interpret the result Round to three decimal places as needed How can the coefficient of determination be interpreted The fraction of the variation in the amount of error b Find the standard error of estimates and interpret the result s thousands of barrels per day Round to three decimal places as needed How can the standard error of estimate be interpreted The standard error of estimate of the amount of that can be explained by the variation in the amount of for 5 847 9 310 of 5 651 5 642 5 352 5 219 5 137 5 031 9 139 9 658 10 085 10 195 10 190 10 012 is is about s The remaining fraction of the variation is unexplained and is due to other factors or to sampling

Hours spent studying x Test score y Find the equation of the regression line for the given data Then construct a scatter plot of the data and draw the regression line The pair of variables have a significant correlation Then use the regression equation to predict the value of y for each of the given x values if meaningful The number of hours 6 students spent for a test and their scores on that test are shown below C 0 38 1 45 OA 96 5 OB 53 3 O C 60 5 2 52 A 53 3 B 60 5 OC 55 7 OD not meaningful b Predict the value of y for x 4 5 Choose the correct answer below A 60 5 B 96 5 OC 55 7 OD not meaningful c Predict the value of y for x 12 Choose the correct answer below Part 5 of 6 4 47 5 64 Points 0 29 of 1 5 69 a x 3 hours c x 12 hours Save b x 4 5 hours d x 3 5 hours

Given the equation of a regression line is y 0 00014x 2 53 determine whether there is a positive linear correlation or a negative linear correlation negative linear correlation Opositive linear correlation

K Two variables have a positive linear correlation Does the dependent variable increase or decrease as the independent variable increases Choose the correct answer below O The dependent variable increases O The dependent variable decreases

K The accompanying data are the number of wins and the earned run averages mean number of earned runs allowed per nine innings pitched for eight baseball pitchers in a recent season Find the equation the regression line Then construct a scatter plot of the data and draw the regression line Then use the regression equation to predict the value of y for each of the given x values if meaningful If the x valu not meaningful to predict the value of y explain why not a x 5 wins b x 10 wins d x 15 wins Click the icon to view the table of numbers of wins and earned run average c x 19 wins The equation of the regression line is y x Round to two decimal places as needed Wins and ERA Wins x 20 18 17 16 14 12 11 9 k Earned run average y 2 72 3 26 2 64 3 69 3 76 4 27 3 85 5 16 X

Which of the following values could not represent a correlation coefficient OA 0 OB 1 O C 1 032 OD 0 927

Two variables have a positive linear correlation Is the slope of the regression line for the variables positive or negative OA The slope is negative As the independent variable increases the dependent variable also tends to increase OB The slope is positive As the independent variable increases the dependent variable tends to decrease OC The slope is negative As the independent variable increases the dependent variable tends to decrease O D The slope is positive As the independent variable increases the dependent variable also tends to increase

K Complete parts a through c using the following data Row 1 Row 2 L 50 0 98 100 0 84 Q Q G An 4 76 50 640 a Find the equation of the regression line for the given data letting Row 1 represent the x values and Row 2 the y values Sketch a scatter plot of the data and draw the regression line Input the values of the slope and intercept for the regression line when Row 1 represents the x values y 3 869 x 93 451 Round to three decimal places as needed Construct a scatter plot of the data and draw the regression line Plot Row 1 on the horizontal axis and Row 2 on the vertical axis Choose the correct graph below OA OB O C O D Q Q 4 79 U 5 95 100 RE 100 5 68 50 5 70 0 Q 5 82 Q 7 57 8 7 63 100 Q 8

K The equation of the regression line is y x B Round to two decimal places as needed The accompanying data are the number of wins and the earned run averages mean number of earned runs allowed per nine innings pitched for eight baseball pitchers in a recent season Find the equation of the regression line Then construct a scatter plot of the data and draw the regression line Then use the regression equation to predict the value of y for each of the given x values if meaningful If the x value is not meaningful to predict the value of y explain why not a x 5 wins b x 10 wins c x 19 wins d x 15 wins Click the icon to view the table of numbers of wins and earned run average KEE O Points 0 of 1 Wins and ERA Wins x 20 18 17 16 14 12 11 Earned run average y 2 72 3 26 2 64 3 69 3 76 4 27 3 85 D Save X

K Use the value of the linear correlation coefficient to calculate the coefficient of determination What does this tell you about the explained variation of the data about the regression line About the unexplained variation r 0 747 Calculate the coefficient of determination Part 1 of 3 0 588 Round to three decimal places That s incorrect The coefficient of determination r2 is the square of the correlation coefficient r h OK X

K The weights in pounds of 6 vehicles and the variability of their braking distances in feet when stopping on a dry surface are shown in the table Can you conclude that there is a significant linear corre between vehicle weight and variability in braking distance on a dry surface Use 0 05 Weight x 5980 5380 D 6500 5100 5860 4800 1 87 1 61 1 65 1 50 1 75 1 91 Variability in braking distance y Click here to view a table of critical values for Student s t distribution Part 2 of 4 Setup the hypothesis for the test Ho p 0 Ha P 0 CAT Identify the critical value s Select the correct choice below and fill in any answer boxes within your choice Round to three decimal places as needed O A The critical values are to and to OB The critical value is W

K Find the equation of the regression line for the given data Then construct a scatter plot of the data and draw the regression line The pair of variables have a significant correlation Then use the regression equation to predict the value of y for each of the given x values if meaningful The number of hours 6 students spent for a test and their scores on that test are shown below Hours spent studying x Test score y Test score 80 0 8 Hours studying 0 38 Q 1 45 Find the regression equation y 4 796 x 38 91 Round the slope to three decimal places as needed Round the y intercept to two decimal places as needed Choose the correct graph below O A OB 2 52 Test score 4 47 804 of 0 8 Hours studying 5 64 O OU 5 69 D www O C Test score 80 0 a x 3 hours c x 12 hours 0 Hours studying b x 4 5 hours d x 3 5 hours OD 80 0 0 8 Hours studying

K The table shows the average weekly wages in dollars for state government employees and federal government employees for 8 years The equation of the regression line is y 1 601x 181 778 Complete parts a and b below Average Weekly Wages state x Average Weekly Wages federal y 763 991 a Find the coefficient of determination and interpret the result r2 0 912 Round to three decimal places as needed How can the coefficient of determination be interpreted 780 1039 The coefficient of determination is the fraction of the variation in average weekly wages for and is represented by 795 1119 809 1140 Points 0 of 1 The remaining fraction of the variation 838 1199 882 1249 916 1285 950 1302 that can be explained by the variation in average weekly wages for is unexplained and is due to other factors or to sampling error

esearcher wanted to determine whether certain accidents were uniformly distributed over the days of the week The ta show the day of the week for n 308 randomly selected accidents Is there reason to believe that the accidents cur with equal frequency with respect to the day of the week at the a 0 05 level of significance Click the icon to view the table Click here to view the Chi Square distribution table Day of the Week Observed Count Expected Count Sunday Monday Tuesday Wednesday Thursday Friday Saturday 45 40 31 41 42 50 59 44 44 44 44 44 44 44 Round to three decimal places as needed What is the test statistic x 10 455 Round to three decimal places as needed What range of P values does x correspond to

ccording to a census company 7 1 of all babies born are of low birth weight An obstetrician wanted to know whether others between the ages of 35 and 39 years give birth to a higher percentage of low birth weight babies She andomly selected 280 births for which the mother was 35 to 39 years old and found 30 low birth weight babies omplete parts a through c below Click the icon to view the chi square distribution table Click here to view page 1 of the standard normal distribution table Click here to view page 2 of the standard normal distribution table Compute the test statistic for this test o 2 36 Round to two decimal places as needed Compute the P value for this test P value 0 009 Round to three decimal places as needed State a conclusion for this test in the context of the obstetrician s question Choose the correct answer below O A Reject the null hypothesis There is not sufficient evidence to conclude that mothers between the ages of 35 and 39 years give birth to a higher percentage of low birth weight babies at the x 0 05 level of significance OB Do not reject the null hypothesis There is sufficient evidence to conclude that mothers between the ages of 35 and 39 years give birth to a higher percentage of low birth weight babies at the x 0 05 level of significance OC Reject the null hypothesis There is sufficient evidence to conclude that mothers between the ages of 35 and 39 years give birth to a higher percentage of low birth weight babies at the x 0 05 level of significance the ages of

Suppose that you are testing the hypotheses Ho 16 vs HA 16 A sample of size 64 results in a sample mean of 15 5 and a sample standard deviauon of 2 a What is the standard error of the mean b What is the critical value of t for a 95 confidence interval c Construct a 95 confidence interval for u d Based on the confidence interval at a 0 025 can you reject Ho Explain a The standard error of the mean is 0 Type an integer or a decimal

You have certainly heard the above claim before Advertisers frequently claim that some percentage of doctors or dentists recommend a given health product It s best to take such claims with a large grain of salt Suppose a recent advertisement claims that 9 out of 10 dentists 90 recommend a certain brand of toothpaste A consumer advocacy group is highly suspicious of this claim and randomly surveys 251 dentists They find that 92 6 of the sample recommends the given brand of toothpaste Using a 0 025 test the hypothesis that the proportion of all dentists who recommend this brand of toothpaste is different than 90 State the null and alternative hypothesis for this test Ho p V 0 9 H PV 0 9 Determine if this test is left tailed right tailed or two tailed two tailed O left tailed Oright tailed Should the standard normal 2 distribution or Student s t distribution be used for this test The Student s t distribution should be used The standard normal z distribution should be used Determine the critical value s for this hypothesis test Round the solution s to two decimal places If more than one critical value exists enter the solutions using a comma separated list 2 81 x Determine the test statistic Round the solution to two decimal places 1 3 X Determine the appropriate conclusion for this hypothesis test The sample data do not provide sufficient evidence to reject the null hypothesis that the proportion of all dentists that recommend this brand of toothpaste is 0 9 and thus we conclude that the proportion of dentists that recommend this brand of toothpaste is likely equal to 0 9 The sample data provide sufficient evidence to reject the null hypothesis that the proportion of all dentists that recommend this brand of toothpaste is 0 9 and thus we conclude that the proportion of dentists that recommend this brand of toothpaste is not equal to 0 9 The sample data do not provide sufficient evidence to reject the alternative hypothesis that the proportion of dentists who recommend this brand of toothpaste is significantly different than 0 9 and thus we conclude that the proportion of all dentists that recommend this brand of toothpaste is likely different than 0 9 The sample data provide sufficient evidence to reject the alternative hypothesis that the proportion of dentists who recommend this brand of toothpaste is significantly different than 0 9 and thus we conclude that the proportion of all dentists that recommend this brand of toothpaste is likely equal to 0 9

Suppose a right tailed hypothesis test for a mean is conducted The test statistic for the hypothesis test was calculated to be 2 886 derived from a sample of size 51 Determine the correct conclusion given the result above Assume the population standard deviation is unknown Use a significance level of 0 05 O Reject H O Fail to reject Ho Reject Ho Fail to reject H Interpret the above conclusion O The sample data do not provide sufficient evidence to reject the alternative hypothessis and conclude that the alternative hypothesis is likely true O The sample data provide sufficient evidence to reject the alternative hypothesis and conclude that the null hypothesis is likely true The sample data provide sufficient evidence to reject the null hypothesis and conclude that the alternative hypothesis is likely true O The sample data do not provide sufficient evidence to reject the null hypothesis and conclude that the null hypothesis is likely true

Which if any of the following pairs are hypotheses for a two tailed test OHo p 0 9 H p 0 9 OHo p 0 6 H p 0 6 O Ho p 0 59 H p0 59 Ho p 0 8 H p 0 8 Ho p 0 49 H p0 49 Ho p 0 18 H p 0 18 Which if any of the following pairs are hypotheses for a one tailed test Ho p 0 6 H p 0 6 O Ho p 0 49 H p0 49 Ho p 0 59 H p0 59 Ho p 0 18 H p 0 18 O Ho p 0 8 H p0 8 O Ho p 0 9 H p 0 9 Which if any of the following pairs are hypotheses for a right tailed test O Ho p 0 49 H p0 49 Ho p 0 18 H p 0 18 Ho p 0 9 H p 0 9 Ho p 0 59 H p0 59 OHo p 0 6 H p 0 6 Ho p 0 8 H p 0 8 Which if any of the following pairs are hypotheses for a left tailed test Ho p 0 9 H p 0 9 Ho p 0 6 H p 0 6 Ho p 0 8 H p0 8 O Ho p 0 59 Ho p 0 49 H p0 59 H p0 49

O Points 0 of 1 The table shows the average weekly wages in dollars for state government employees and federal government employees for 8 years The equation of the regression line is y 1 601x 181 778 Complete parts a and b below Average Weekly Wages state x Average Weekly Wages federal y 763 991 Part 1 of 4 a Find the coefficient of determination and interpret the result 12 0 Round to three decimal places as needed 780 1039 795 1119 809 1140 838 1199 882 1249 916 1285 950 1302 D

rrelation and Hours spent studying x Test score y Find the equation of the regression line for the given data Then construct a scatter plot of the data and draw the regression line The pair of variables have a significant correlation Then use the regression equation to predict the value of y for each of the given x values if meaningful The number of hours 6 students spent for a test and their scores on that test are shown below 0 38 1 45 2 52 4 47 5 64 5 69 CCCOD a x 3 hours c x 12 hours Find the regression equation x D X Round the slope to three decimal places as needed Round the y intercept to two decimal places as needed b x 4 5 hours d x 3 5 hours

8 Correlation and Regression K Complete parts a through c using the following data Row 1 Row 2 0 98 0 84 4 76 Part 2 of 7 4 79 5 95 CHS 5 68 O Points 0 of 1 5 70 5 82 7 57 7 63 a Find the equation of the regression line for the given data letting Row 1 represent the x values and Row 2 the y values Sketch a scatter plot of the data and draw the regression line Input the values of the slope and intercept for the regression line when Row 1 represents the x values y x Round to three decimal places as needed D

Part 1 of 6 The equation of the regression line is y x 0 Round to two decimal places as needed O Points 0 of 1 The accompanying data are the number of wins and the earned run averages mean number of earned runs allowed per nine innings pitched for eight baseball pitchers in a recent season Find the equation of the regression line Then construct a scatter plot of the data and draw the regression line Then use the regression equation to predict the value of y for each of the given x values it meaningful If the x value is not meaningful to predict the value of y explain why not a x 5 wins b x 10 wins c x 19 wins d x 15 wins Click the icon to view the table of numbers of wins and earned run average Save

K Explain what it means for two variables to have a bivariate normal distribution Choose the correct answer below OA Two variables have a bivariate normal distribution when for any fixed values of x the corresponding values of y are normally distributed and for any fixed values of y the corresponding value normally distributed OB Two variables have a bivariate normal distribution when for any fixed values of x the corresponding values of y are normally distributed OC Two variables have a bivariate normal distribution when for any fixed values of y the corresponding values of x are normally distributed OD Two variables have a bivariate normal distribution when the values of x and y are both normally distributed

ployee 001 002 003 004 005 006 007 Location YYZ YVR YOW YOW YYZ YEG YYZ Department Salary 50000 45000 40000 45000 50000 60000 50000 HR IT HR MKTG IT SALES MKTG Using the table shown above write a query to find the total salary for all location department combos Note The Final table should also contain subtotals for each

A regulation softball should weigh 188 grams A company produces softballs for the NPF To help ensure a high degree softballs is drawn from the production line every 30 minutes and each softball is measured for accuracy If accuracy a random sample of 24 the average weight of the sample is found to be significantly different than 188 grams then the production l ne is shut down for inspection The mean weight of a recent sample of 24 softballs was found to be 176 85 grams Use the p value method to test the hypothesis that the mean weight of a softball produced by this company is different than 188 grams using a significance level of 5 Assume that the distribution of weights of all softballs produced by this company is known to be approximately normally distributed with a standard deviation of 24 3 grams State the null and alternative hypothesis for this test Ho V H 2 V Determine if this test is left tailed right tailed or two tailed Oright tailed Otwo tailed Oleft tailed Should the standard normal z distribution or Student s t distribution be used for this test The standard normal z distribution should be used The Student s t distribution should be used Determine the test statistic for the hypothesis test Round the solution to two decimal places Determine the p value for the hypothesis test Round the solution to four decimal places Determine the appropriate conclusion for this hypothesis test O The sample data provide sufficient evidence to reject the null hypothesis that the mean softball weight produced by this company is 188 grams and thus we conclude that the production line needs to be shut down and inspected The sample data do not provide sufficient evidence to reject the null hypothesis that the mean softball weight produced by this company is 188 grams and thus we conclude that the production line is operating correctly and does not need inspection O The sample data provide sufficient evidence to reject the alternative hypothesis that mean softball weight of softballs produced by this company is significantly different than 188 ounces and thus we conclude that the production line is operating correctly and does not need inspection The sample data do not provide sufficient evidence to reject the alternative hypothesis that mean softball weight of softballs produced by this company is significantly different than 188 ounces and thus we conclude that the production line needs to be shut down and inspected

Hospital emergency rooms ERS have a bad reputation for long wait times To improve their image many hospitals have worked hard to reduce their ER walt times and frequently advertise their improved low ER wait times Cleveland Clinic Martain Health recently advertised a 14 minute or leis wait time at their ER An accreditation agency is suspicious of this low advertised wait time and would like to test the hospital s claim A random sample of 137 ER visits to Cleveland Clinic Martain Health was examined and the mean wait time of the sample was found to be 14 36 minutes Using a 0 1 can the accreditation agency conclude that the hospital s claim about ER wait times is false Assume that the standard deviation of the wait times of all ER visits at Cleveland Clinic Martain Health is known to be 2 43 minutes Use the critical value method State the null and alternative hypothesis for this test Ho V H V Determine if this test is left tailed right tailed or two tailed Oleft tailed Oright tailed Otwo tailed Should the standard normal a distribution or Student s t distribution be used for this test The standard normal 2 distribution should be used O The Student s t distribution should be used Determine the critical value s for this hypothesis test Round the solution s to two decimal places If more than one critical value exists enter the solutions using a comma separated list Determine the test statistic Round the solution to two decimal places etermine the appropriate conclusion for this hypothesis test O The sample data do not provide sufficient evidence to reject the alternative hypothesis that the mean ER wait time at is greater than 14 minutes and thus we conclude that the hospital s claim that the mean ER wait time is 14 minutes or less is likely false The sample data do not provide sufficient evidence to reject the null hypothesis that the mean ER wait time at is 14 less minutes and thus we conclude that the hospital s claim that the mean ER wait time is 14 or less minutes is likely true The sample data provide sufficient evidence to reject the null hypothesis that the mean ER wait time at is 14 less minutes and thus we conclude that the hospital s claim that the mean ER wait time is 14 or less minutes is likely false The sample data provide sufficient evidence to reject the alternative hypothesis that the mean ER wait time at is greater than 14 minutes and thus we conclude that the hospital s claim that the mean ER wait time is 14 minutes or less is likely true

Each year researchers at the U S Bureau of Labor Statistics BLS administer the American Time Use Survey ATUS Researchers estimate the average amount of time Americans spend on daily activities such as working housework and leisure activities In particular one activity that is of interest is the average amount of time Americans spend watching television each day A researcher complied a random sample of 12 Americans and asked each person how much time they spent watching television each day The results are given below 4 3 9 2 2 5 3 9 4 7 2 3 9 1 4 3 3 6 3 1 Determine the point estimate and the sample standard deviation s Round the solutions to four decimal places if necessary Using a 98 confidence level determine the margin of error E and a confidence interval for the average time Americans spend watching television each day Report the confidence interval using interval notation Round solutions to two decimal places if necessary The margin of error is given by E 98 confidence interval is given by

According to a census company 7 1 of all babies born are of low birth weight An obstetrician wanted to know whether mothers between the ages of 35 and 39 years give birth to a higher percentage of low birth weight babies She randomly selected 280 births for which the mother was 35 to 39 years old and found 30 low birth weight babies Complete parts a through c below Click the icon to view the chi square distribution table Click here to view page 1 of the standard normal distribution table Click here to view page 2 of the standard normal distribution table GELING Compute the test statistic for this test x 5 54534 Round to three decimal places as needed Compute the P value for this test The P value is between 0 01 and 0 025 State a conclusion for this test in the context of the obstetrician s question Choose the correct answer below OA Reject the null hypothesis There is not sufficient evidence to conclude that mothers between the ages of 35 and 39 years give birth to a higher percentage of low birth weight babies at the x 0 05 level of significance OB Reject the null hypothesis There is sufficient evidence to conclude that mothers between the ages of 35 and 39 years give birth to a higher percentage of low birth weight babies at the x 0 05 level of significance OC Do not reject the null hypothesis There is not sufficient evidence to conclude that mothers between the ages of 35 and 39 years give birth to a higher percentage of low birth weight babies at the a 0 05 level of significance OD Do not reject the null hypothesis There is sufficient evidence to conclude that mothers between the ages of 35

The daily sales at a convenience store produce a normal distribution with a mean of 1 897 and a standard deviation of 137 Determine the probability that the sales on a given day at this store are more than 1 929 00 6204 08208 008M

The Graduate Management Admission Test GMAT scores of all examinees who took the test this yea produced a normal distribution with a mean of 601 and a standard deviation of 26 Determine the percentage of all scores between 528 and 622 Owes 078 79 079 045 0 0 25

According to the National Institutes of Health 68 of adults experience some form of lactose intolerance Determine the probability that less than 71 of adults in a sample of 684 experience some form of lactone erance 00378 Cas199

The shape of a normal distribution curve is determined by its O median O standard deviation O mean O mode

At a large university 26 of all students live on campus Suppose a random sample of 210 students is selected from this university and the sample proportion is defined as the proportion of students in the sample who live on campus Determine the standard deviation of the sampling distribution of 00 357 00 8579 Cami

For the standard normal distribution the area beween z 2 25 and z 0 c 00 9989 003 00 9616

For the standard normal distribution the area beween z 2 03 and z 2 41 is 00 5793 0 0073 0 0 9708

of 2 with sample size n taken out of a population of size N For a sampling distribution O the mean is and the standard deviation is a O the mean is jy0 and the standard deviation is a 1 O the mean is and the standard deviation is a N O the mean is and the standard deviation is ay

Determine the two values of a such that the middle 78 of the data lle between the two zvalues Oz 1 23 and a 1 23 Ox 0 5 and z 0 5 02 0 81 and 2 0 81 Oz 1 28 and 2 1 28

the mean of a normal distribution is increased then the graph of the distribution O shifts right O increases vertically O does not change O decreases vertically O shifts left

Let X be a normally distributed variable The z score of the mean of the distribution is equal to 0 1 00 Oas 043

For the standard normal distribution O the mean is 1 and the standard deviation is 0 O the mean is 0 and the standard deviation is 0 5 O the mean is 0 and the standard deviation is 1 O the mean is 1 and the standard deviation is 1 O the mean is 0 and the standard deviation is

Determine the value of such that the area to the left of z is 0 2877 0 1 79 Oz 0 61 0z 0 15 Oz 0 56

A sample proportion is O The number of observations in the population that possess a given characteristic O the percent in decimal form of the population that possesses a given characteristic O The number of observations in the sample that posses a given characteristic O the percent in decimal form of the sample that possesses a given characteristic

Let I have a normal distribution with a mean of 161 and a standard deviation of 20 The value that comesponds to z 1 82 01244

Suppose a population distribution has a mear of 64 and a a random sample of 144 observations from this population has a mean of 51 3 The sampling error of Z is 05 8 034 1 016 0 12 7

For the standard normal distribution the area to the right of z 5 71 is 01 005 0