Statistics Questions

You measure 38 dogs weights and find they have a mean weight of 30 ounces Assume the population standard deviation is 6 7 ounces Based on this construct a 95 confidence interval for the true population mean dog weight Give your answers as decimals to two places

9 15 points Cable TV choices A telecommunications company provided Its cable TV subscribers with free access to a new sports channel for a period of one month It then chose a sample of 400 television viewers and asked them whether they would be willing to pay an extra 10 per month to continue to access the channel A total of 28 of the 400 replied that they would be willing to pay The marketing director of the company claims that less than 9 of all its subscribers would pay for the channel Can you conclude that the director s claim is true Use the a 0 10 level of significance and the P value method with the table

10 point Babies According to a recent report a sample of 300 one year old baby boys in the United States had a mean weight of 25 5 pounds Assume the population standard deviation is a 5 5 pounds 2 Construct a 99 confidence interval for the mean weight of all one year old baby boys in the United States Round the final answer to at least one decimal place stege ort

The lifetime of a certain brand of electric light bulb is known to have a standard deviation of 47 hours Suppose that a random sample of 80 bulbs of this brand has a mean lifetime of 479 hours Find a 90 confidence Interval for the true mean lifetime of all light bulbs of this brand Then give its lower limit and upper limit Carry your Intermediate computations to at least three decimal places Round your answers to one decimal place If necessary consult a list of formulas Lower limit Upper limit

15 points 7 House prices Data from the National Association of Realtors indicates that the mean price of a home in Denver bu Colorado In 2012 was 260 7 thousand dollars A random sample of 70 homes sold in 2013 had a mean price of 295 thousand dollars Assume the population standard deviation is a 148 Can you conclude the mean price in 2013 is greater than the mean price in 2012 Use the a 0 10 level of significance and the P value method with the table

6 Determine whether the outcome is a Type I error a Type II error or a correct decision A test is made of H 32 versus H 32 The true value of u is 3S and H is not rejected

4 10 points Changing jobs A sociologist sampled 228 people who work in computer related jobs and found that 51 of them have changed jobs in the past 6 months Construct a 99 5 confidence interval for the proportion of those who work in computer related jobs who have changed jobs in the past six months Round your final answer to 3 digits after the decimal point

7 points PC Gaming A computer magazine editor claims that the mean cost of a gaming computer is 1250 A test is made of Hol 1250 versus H u 1250 The null hypothesis is not rejected State an appropriate conclusion

3 10 points Let s go to the movies A random sample of 42 Foreign Language movies made since 2000 had a mean length of 110 2 minutes with a standard deviation of 12 3 minutes Construct a 90 confidence interval for the true mean length of all Foreign Language movies made since 2000 Round the final answer to at least one decimal place

10 points Find the critical value 2 needed to construct a confidence interval with level 85 Round your final answer to 2 digits after the decimal point

and 12 Question 26 of 82 The bar graph below shows that as costs changed over the decades a group of people devoted less of their budget to groceries Percentage of Total Spending on Food Percent of Total Spending 30 24 21 18 14 12 6 possible This question 1 point s possible 9 7 1950 1970 1990 2010 In 1950 the group spent 21 of their budget on food This has decreased at an average rate of approximately 0 23 per year since then Find a linear function in slope intercept form that models the percentage of total spending p x by the group x years after 1950 CHIB Resume later Submit quiz The equation p x models the given description Use integers or decimals for any numbers in the expression

Assume that a normal distribution of data has a mean of 17 and a standard deviation of 5 Use the empirical rule to find the percentage of values that lie below 2 What percentage of values lie below 2

Complete the problems to find the profit or loss 1 You paid 1 829 for 40 shares of JTT stock You sold the stock for 61 50 per share The commission you paid was 35 50 2 You paid 24 000 for 1 000 shares of EXO stock You sold the stock for 22 50 per share The commission you paid was 49 95

greater than 5 You want to test this claim To do so you collect a large random sample from the population and perform a hypothesis test at the o os level of significance To start this test you write the null hypothesis Ho and the alternative hypothesis H as follows Hu 5 H 5 Suppose you also know the following information The value of the test statistic based on the sample is 1 717 rounded to 3 decimal places The p value is 0 043 rounded to 3 decimal places a Complete the steps below for this hypothesis test Standard Normal Distribution Step 1 Select one tailed or two tailed O One tailed O Two tailed Step 2 Enter the test statistic Round to 3 decimal places Step 3 Shade the area represented by the p value Step 4 Enter the p value Round to 3 decimal places 03 significance the null hypothesis is rejected O Since the p value is greater than the level of significance the null hypothesis is not rejected 02 0 1 X b Based on your answer to part a which statement below is true Since the p value is less than or equal to the level of significance the null hypothesis is rejected O Since the p value is less than or equal to the level of significance the null hypothesis is not rejected O Since the p value is greater than the level of S S

0 20 10 18 0 21 40 Question 43 2 points Given the 5 summary statistics of a data set Minimum 10 Lower Quartile 12 Median Upper Quartile Maximum 13 16 50 60 Which is the only data point below that could be defined as an outlier given a data point x is an outlier if x Q 1 5 IQR or x Q 15 IQR

2 5 38 41 30 33 36 39 42 Question 47 2 points A high school student spends an average of 6 hours 6 on their phone a day with a standard deviation of 2 5 hours 25 If samples of size 16 n 16 were taken from the population what would be the standard deviation of the sample means 0 156 0 500

O 33 36 39 42 Question 50 2 points What is the critical value 24 associated with a 95 confidence interval SOLA 1904 2 anni 0 950 1 645 1 960 2 575 95 Uncal Vave 2 apore

Question 46 2 points Determine the area under the normal curve between the z scores z 0 8 and 1 6 as shown in the graph 0 267 0 684 0 733 0 786 Question 47 2 points A high school student spends an nuor 0 8 a 22 2 scorez 091

Sampie Question 37 2 points Which type of sampling method is being employed in the following example A study was being conducted after a tsunami The researcher was trying to assess the needs of the victims in a single downtown high rise apartment building So she sent a messenger to ask one person on each floor what their needs were to get an idea of what was needed to support the people in the building Simple Random Sampling Stratified Sampling Cluster Sampling Sampling of Convenience

A wedding website states that the average cost of a wedding is 27 825 One concerned bride hopes that the average is less than reported To see if her hope is correct she surveys 46 recently married couples and finds that the average cost of weddings in the sample was 26 321 Assuming that the population standard deviation is 6721 is there sufficient evidence to support the bride s hope at the 0 05 level of significance Step 3 of 3 Draw a conclusion and interpret the decision Answer 0 5 Points Keypad Keyboard Shortcuts We fail to reject the null hypothesis and conclude that there is sufficient evidence at a 0 05 level O of significance to support the bride s hope that the mean cost of a wedding is less than 27 825 We reject the null hypothesis and conclude that there is insufficient evidence at a 0 05 level of significance to support the bride s hope that the mean cost of a wedding is less than 27 825 We fail to reject the null hypothesis and conclude that there is insufficient evidence at a 0 05 O level of significance to support the bride s hope that the mean cost of a wedding is less than 27 825 We reject the null hypothesis and conclude that there is sufficient evidence at a 0 05 level of significance to support the bride s hope that the mean cost of a wedding is less than 27 825

A manufacturer of potato chips would like to know whether its bag filling machine works correctly at the 421 gram setting It is believed that the machine is underfilling the bags A 44 bag sample had a mean of 411 grams Assume the population standard deviation is known to be 26 A level of significance of 0 1 will be used State the null and alternative hypotheses Answer 1 Point Ho Keypad Keyboard Shortcuts

The National Academy of Science reported that 33 of research in mathematics is published by US authors The mathematics chairperson of a prestigious university wishes to test the claim that this percentage is no longer 33 He has no indication of whether the percentage has increased or decreased since that time He surveys a simple random sample of 234 recent articles published by reputable mathematics research journals and finds that 62 of these articles have US authors Does this evidence support the mathematics chairperson s claim that the percentage is no longer 33 Use a 0 05 level of significance Step 1 of 3 State the null and alternative hypotheses for the test Fill in the blank below Answer 05 Points Ho p 0 33 Ha P 0 33 Keypad

A researcher believes that 5 of pet dogs in Europe are Labradors If the researcher is right what is the probability that the proportion of Labradors in a sample of 433 pet dogs woul differ from the population proportion by more than 3 Round your answer to four decimal places

The mean output of a certain type of amplifier is 117 watts with a variance of 100 If 42 amplifiers are sampled what is the probability that the mean of the sample would differ from the population mean by less than 3 3 watts Round your answer to four decimal places

Decide if the statement is True or False Answer 2 Points A sampling distribution refers to individuals rather than groups O False

Suppose the following estimated regression equation was determined to predict salary based on years of experien Estimated Salary What is the estimated salary for an employee with 3 years of experience 23 932 92 2352 69 Years of Experience

Score on last try 0 of 1 pts See Details for more Next question You can retry this question below If you randomly select a letter from the phrase Ichiro Suzuki is at the top of the lineup what is the probability that you select a vowel Your answer must be in the form of a reduced fraction Question Help Post to forum Submit Question

Score on last try 0 of 1 pts See Details for more You can retry this question below Suppose a jar contains 19 red marbles and 26 blue marbles If you reach in the jar and pull out 2 marbles at random at the same time find the probability that both are red Question Help Video Post to forum Submit Question

Using your favorite statistics software package you generate a scatter plot with a regression equation and correlation coefficient The regression equation is reported as y 66 69x 14 13 and the r 0 082 What proportion of the variation in y can be explained by the variation in the values of x r Report answer as a percentage accurate to one decimal place

The mean height of a certain kind of plant is 167 centimeters Suppose we want to carry out a hypothesis test to see if the mean height when these plants are treated with a certain chemical differs from 167 State the null hypothesis H and the alternative hypothesis that we would use for this test Ho H D X O P S 0 0

1 30 students in SUNY New Paltz plan to have lunch in New Paltz There are plenty of restaurants in New Paltz and they have 20 restaurants they can choose from Each student randomly chooses one place with equal probability a Let X be the number of restaurants that no one chooses Find the expectation of X I

Answer the following questions on the F test statistic Complete parts a through d below a If s represents the larger of two sample variances can the F test statistic ever be less than 1 O A No because the ratio OB Yes because the ratio OC No because the ratio 2 2 OD Yes because the ratio will always be greater than 1 2 S 2 52 2 S will always be greater than 1 2 2 will always be less than 1 S 2 2 will always be less than 1

Large samples of women and men are obtained and the hemoglobin level is measured in each subject Here is the 95 confidence interval for the difference between the two population means where the measures from women correspond to population 1 and the measures from men correspond to population 2 1 76 g dL H1 H2 1 62 g dL Complete parts a through c below a What does the confidence interval suggest about equality of the mean hemoglobin level in women and the mean hemoglobin level in men Because the confidence interval it appears that there men Type an integer or a decimal Do not round a significant difference between the mean level of hemoglobin in women and the mean level of hemoglobin in

The radioactive isotope Pu 240 has a half life of about 6564 years If 50 grams present now how much will be left 3 000 years from now Round to the nearest thousandth of a gram Oa 38 011 grams Ob 39 123 grams O c 36 424 grams d 35 012 grams

On the Orange River a particular boat traveling with the current can travel 72 miles in 2 hours Traveling against the current the boat can travel 54 miles in 2 hours Find the speed of the current The speed of the current is Question 22 1 point Saved A miles per hour

The graph of y 52 13 70 is the graph of y 5 shifted how State the direction of each shift followed by the number of units of that shift up down down and right left left I A units A units

A chemist needs to mix a 10 alcohol solution with a 70 alcohol solution to get 15 liters of a 46 alcohol solution How many liters of the 10 solution should be used How many liters of the 70 solution should be used Use this many liters of the 10 solution and this many liters of the 70 solution A A

How long does it take a 5200 investment to double when it is invested at 3 7 interest compounded quarterly Use the compound interest formula Round to the nearest hundredth of a year A years

After studying all night for a final exam a bleary eyed student randomly grabs 2 socks from a drawer containing 13 black socks 8 brown socks and 2 blue socks all mixed toget probability that the student grabs a matched pair The probability of a matched pair is Type an integer or a simplified fraction GELCH

A reader wrote the following passage to a column in a magazine You have 6 envelopes to pick from Two thirds that is 4 are empty One third that is 2 contain a 100 bill You re told to choose 2 envelopes at random Which least one 100 bill or 2 that you ll get no 100 bill at all Find the two probabilities The probability that you will get at least one 100 bill is Type an integer or a simplified fraction and the probability that you ll get no 100 bill at all is

For the experiment described below let x determine a random variable and use your knowledge of probability to prepare a probability distribution The sums that appear when two fair four sided dice tetrahedrons with sides 3 6 9 and 12 are tossed Complete the probability distribution below Sum Probability Sum Probability 6 18 9 21 12 24 15 Type simplified fractions

wo cards are drawn at random from an ordinary deck of 52 cards What is the probability that all 2 are the same ne probability is P E ype an integer or a simplified fraction

K Twenty five slips of paper are each marked with a different letter of the alphabet and placed in a basket A slip is pulled out its letter recorded in the order in which the slip was drawn a replaced This is done 3 times Find the probability that a word with no repetition of letters is formed Which of the following can be used to find the probability Choose the correct answer below OA 25 24 231 325 O C OE 31 31 25 3 1 31 25 3 O G 3 31 The probability is Type an integer or decimal rounded to four decimal places as needed OB 253 25 24 23 OD P 25 3 OF 25 24 23 253 OH C 25 3

Three crows 6 blue jays and 7 starlings sit in a random order on a section of telephone wire Find the probability that birds of a feather flock together that is that a together www The probability is Use scientific notation Use the multiplication symbol in the math palette as needed Round to three decimal places as needed

Find the expected payback for a game in which you bet 8 on any number from 0 to 999 If your number comes up you get 500 The expected payback is Round to the nearest cent as needed

A survey found that customers are overcharged by price scanning systems on average on 1 65 of items Suppose a customer purchases 14 items Find the following pr A customer is overcharged on 1 item The probability is Round to six decimal places as needed

A die is rolled 10 times Find the probability of rolling no more than 4 sixes The probability of rolling no more than 4 sixes is Type an integer or decimal rounded to four decimal places as needed Round all intermediate values to four decimal places as nee

A bag contains 5 red balls and 3 blue balls If 2 balls are selected at random find the probability of selecting 2 red balls Which of the following can be used to find the probability Choose the correct answer below OA C 5 2 C 8 2 OC C 5 2 81 OE P 5 2 P 8 2 G 81 2151 The probability is Type an integer or a simplified fraction OB C 8 2 OD C 8 5 OF P 8 5 OH 81 51

A die is rolled 4 times Find the probability of rolling exactly 1 five Use the formula for binomial probability to calculate the probability of rolling exactly 1 five Assume success in this case is rolling a 1 P x successes in n trials C n x p 1 p C 4 1 Type integers or fractions CCX The probability is Round to four decimal places as needed

A survey finds that customers are overcharged by price scanning systems on average on 1 70 of items Suppose a customer purchases 10 items Find the following proba A customer is not overcharged for any itern The probability is Round to four decimal places as needed www