Statistics Questions and Answers

5 For each of the following studies state whether random sampling or random assignment was likely to have been used For each what is the population to which we want to generalize the results b A counseling center director wanted to compare the length of therapy in weeks for students who came in for treatment for depression versus students who came in for treatment for anxiety She wanted to report these data to the university administrators to help develop next year s budget

3 Credit card companies will often call cardholders if the pattern of use indicates that the card might have been stolen Let s say that you charge an average of 280 a month on your credit card with a standard deviation of 75 The credit card company will call you anytime your purchases for the month exceed the 98th percentile What is the dollar amount beyond which you ll get a call from your credit card company That is what dollar amount is at the 98th percentile for your purchase history

Big Trail Running Company has started to produce r best reflect their overall manufacturing overhead usa Estimated Manufacturing Overhead by Department Trail Running Shoes Machin 500 00 340 00

K Lucas Industries uses departmental overhead rate departmental overhead rate of 50 per machine h and machine hours in the two departments Assembly

Macmillan Learning Classify the outcomes described in each scen Mutually exclus

10 Fun Ways to Flirt In a Microsoft Instant Messaging survey respondents were asked to choose the most fun way to flirt and the accompanying table is based on the results E mail In person Instant message P x 0 06 0 55 0 24

e Probability Distributions Identifying Probability Distributions In Exercises 7 14 deviation If a probability distribution is not given identify the requirements that are not ability distribution is given If a probability distribution is given find its mean and standard satisfied 7 Genetic Disorder Five males with an X linked genetic disorder have one child each The random variable x is the number of chil dren among the five who inherit the X linked genetic disorder X 0 1 2 3 4 5 P x 0 031 0 156 0 313 0 313 0 156 0 031

Compute the linear correlation coefficient for the data below rounding to three decimal places X 1 3 4 2 1 60 7 y 8 9 4 0 1 2 5 A 0 671 B 0 778 C 0 995 D 0 885 5 2 3 0 7 8

point s possible The data below are the final exam scores of 10 randomly selected calculus students and the number of hours they slept the night before the exam Compute the linear correlation coefficient rounding to three decimal places Hours x Scores y OA 0 654 OB 0 761 OC 0 847 D 0 991 7 63 9 78 6 58 12 86 6 64 8 76 8 83 9 88 10 88 70 69

In an area of the Great Plains records were kept on the relationship between the rainfall in inches and the yield of wheat bushels per acre Find the least squares regression line for the given data Round the least squares regress line values to three decimal places Rainfall x 10 5 8 8 13 4 12 5 18 8 10 3 7 0 15 6 16 0 Yield y 50 5 46 2 58 8 59 0 82 4 49 2 31 9 76 0 78 8 OA y 4267x 4 379 OB y 4 267x 4 379 OC y 4 379x 4 267 OD 4 379x 4 267

A manager wishes to determine the relationship between the number of years her sales representatives have been employed by the firm and their amount of sales in thousands of dollars per month Find the least squares regression line for the given data What would be the predicted sales if the sales representative was employed by the firm for 30 years Is this reasonable Why or why not Round the least squares regression line values to two decimal places Years employed x 2 Sales y 31 3 10 33 78 7 62 8 15 65 3 1 110 61 48 55 120 OA y 3 53x 37 92 143 820 Yes it is reasonable OB y 3 53x 37 92 143 820 No it is not reasonable 30 years of employment is well outside the scope of the model OC 3 53x 37 92 67 980 Yes it is reasonable OD 3 53x 37 92 67 980 No it is not reasonable 30 years of employment is well outside the scope of the model

Use the least squares regression equation to predict the value of y for x 4 7 rounding to three decimal places 5 1 2 0 2 3 40 2 6 1 3 6 8 10 X y A 0 495 OB 4 689 C 9 304 D 10 407 3 8 4 9

What effect will an influential observation have upon the graph of the least squares regression line OA It will pull the graph toward the observation OB It will have no effect OC It will lower the value of the correlation coefficient to make further analysis meaningless OD It will push the graph away from the observation

The data below are the final exam scores of 10 randomly selected history students and the number of hours they slept the night before the exam Find the least squares regression line for the given data What would be the predicted score for a history student who slept 7 hours the previous night Is this a reasonable question Round the least squares regression line values to two decimal places and round the predicted score to the nearest whole number Hours x Scores y 3 5 2 8 2 4 4 5 6 30 65 80 60 88 66 78 85 90 90 71 OA y 5 04x 56 11 91 Yes it is reasonable OB y 5 04x 56 11 21 Yes it is reasonable OC y 5 04x 56 11 91 No it is not reasonable 7 hours is well outside the scope of the model

Compute the linear correlation coefficient between the two variables rounding to three decimal pla whether a linear relation exists The table below shows the ages and weights in pounds of 9 randomly selected tennis coaches Age x 40 43 47 50 Weight pounds y 120 124 127 135 53 55 59 63 67 146 149 152 154 156 A r 0 908 linear relation exists OB r 0 906 no linear relation exists OC r 0 960 linear relation exists D r 0 960 no linear relation exists

Find the equation of the least squares regression line for the given data Round values to three decimal places 5 3 4 1 1 8 9 1 2 X y 10 OA y 2 097x 0 552 OB y 2 097x 0 552 OC y 0 552x 2 097 OD y 0 522x 2 097 2 6 0 1 2 3 3 6 40 8

The measures the proportion of total variation in the response variable that is explained by the least squares regression line A sum of the residuals squared B slope of the regression line C linear correlation coefficient D coefficient of determination

Fill in the blanks Given the following least squares regression equation y 173 74x we estimate y to each 1 unit increase in x A increase 173 B increase 74 C decrease 173 OD decrease 74 by Wi

The data below are the number of absences and the final grades of 9 randomly selected students from a literature class Find the least squares regression line for the given data What would be the predicted final grade if a student was absent 14 times Round the least squares regression line values to two decimal places Round the predicted grade to the nearest whole number Number of absences x Final grade y 0 50 3 6 4 9 2 15 8 98 86 80 82 71 92 55 76 82 OA 2 75x 96 14 134 64 OC y 96 14x 2 75 1343 OB 96 14x 2 75 1343 OD 2 75x 96 14 58

Fill in the blank The coefficient of determination is the A square root B opposite C square D reciprocal of the linear correlation coefficient

Which of the following statements about the least squares regression line is correct OA The least squares regression line maximizes the sum of the residuals squared B The least squares regression line maximizes the mean difference between the residuals square C The least squares regression line minimizes the sum of the residuals squared D The least squares regression line minimizes the mean difference between the residuals squared

For a given data set what will the equation of the least squares regression line always pass through OA every point in the given data set OC the y intercept and the slope OD at least two point in the given data set

Given that the least squares regression line is y 3 5x 1 7 what is the best predicted value for y given x 2 37 OA 9 75 OB 6 35 OC 6 35 O

What is a variable that is related to either the response variable or the predictor variable or both but which is excluded from the analysis called OA lurking variable O B discrete variable OC random variable D qualitative variable

A traffic officer is compiling information about the relationship between the hour of the day and the speed over the limit at which the motorist is ticketed He computes a correlation coefficient of 0 12 What does this tell the officer OA There is a strong negative linear correlation B There is a strong positive linear correlation OC There is a quadratic relationship between the variables There is little evidence of a linear correlation D

Question list KE Cornwell Products has adopted an indirect

er plot of eruption data Tume between Eruptions vs Length of Eruption 11 4 11 0 Time Print 118 12 2 12 0 Done Q 20 X o following data represent the time between eruptions d the length of eruption for 8 randomly selected geyser uptions The coefficient of determination is 90 0 ovide an interpretation of this value ck here to view a scatter plot of the data ck here to view a residual plot of the data Time x 12 19 11 63 12 03 12 16 11 34 o coefficient of determination is found to be 90 0 Provide an inter of the variation in tim o least squares regression line explains ype an integer or a decimal Do not round Length y 1 85 1 68 1 83 1 82 1 66 Resdial Time x 11 69 12 11 11 58 11 74 0 10 0 004 0 00 0 04 0 02 0 00 0 02 0 04 0 007 Length 1 69 Residual plot of erup data 1 83 1 73 1 74 Residuals vs Time

signment 6 Two Sample Hypothesis K To assess the effectiveness of a cola video ad for cola B a rando ad being tested cola B Participants then answered a series of q value the more likeable the ad State your findings and conclusio Click the icon to view the data table of the adindex ratings Compute the descriptive statistics Find the mean of the adindex Round to two decimal places as needed

K Let n 80 X 10 n 80 a At the 0 01 level of signific Determine the null and alter OA Ho 2 H OC Ho ST H

ssignment 6 Two Sample Hypothesis 3 K Does Cable Video on Demand VOD D4 increase a indicated that the ad made them want to visit the brand Click the icon to view the data on ad effectiveness a Set up the null and alternative hypotheses to try to Let population 1 correspond to VOD D4 viewers and

TAT1800 Business Statistics SP1 2023 Question list Question 1 Question 2 Question 3 K Is there a difference in the satisfaction rating of traditional ce a contract The accompanying table contains the satisfactio Click the icon to view the data on cellphone provider ra a Assuming that the population variances from both types of Let population 1 be the ratings of the traditional cellphone pr OA Ho H1 12 0 H H H 0

PI 2023 Lesson 6 A recent study found that 62 children who watched a watched a commercial for an alternative food snack deviation for the children who watched the alternative a Assuming that the population variances are equal

What is a Market Economic System O O Economic Systems are based on the concept of free markets Based on a central authority Based on both free market and government control All of the Above

What is a O O mm and Econo System Orders from the U S Armed Forces Is run by a dominant centralized authority usually the government that controls a O O significant portion of the economic structure Run by the free market A system that has both free market command economic principles

Command Economic System is also known as O O O O Capitalism Mixed Economy Traditional Communism

Below are scores for two children who took a state standardized test e g SOL For each of these examples explain the percentile in plain English Explain this as you would to a parent who has never taken statistics 1 Maria is at the 98th percentile on the state standardized test What was the child s z score 2 Jon s z score was 1 What is the child s percentile

Dave wants to buy a new collar for each of his 3 cats The collars come in a choice of 5 different colors Step 2 of 2 How many selections of collars are possible if repetitions of colors are not allowed

Question 19 o hether the following statement is true or false If it is f atio level cannot be put in order

Paolo s Pizzeria offers 4 types of crust 6 toppings and 7 kinds of cheese for the mega calzone How many different mega calzones can be made if a mega calzone contains 3 different toppings and 2 different cheeses

Question 17 of 31 graph to the right shows the annual number of fatalities in thousands listed on the horizontal and vertical es in the figure

e correct answer below Question e whether the following statement is true or false ble blind experiment is used to increase the plac

Question 29 of 31 1 002 adults in a country were asked whether they favor or oppose t mbryos Among the respondents 48 said that they were in favor the population in the given problem Choose the correct answer belo 48 of the 1 002 adults selected The 1 002 adults selected

tify the sample used in the study the correct answer below Question 30 of 31 ent study on the effects of sleep and test results volunteers took a m s correctly on the math test than were sleep deprived volunteers C

Question 26 of 31 ey numbers for players on a soccer team are listed below 11 56 6 23 3 20 35 27 2 29 5 13 the level of measurement of the data set Explain your reasoning

K of measu Select all the levels of mea A Interval B Ordinal C Nominal D Ratio

Que e whether the statement is true or false If es of calculations can be performed with da

the data set s level of measurement ual salaries for all teachers in a particula ratio interval ordinal nominal

ages of students in a statistic class O A ordinal OB interval O C ratio OD nominal

and N Choose the correct answer below Question 23 Determine whether the underlined numerical value is a parame In a poll of a sample of 12 000 adults in a certain city 12 sai O A Parameter because the data set of all adults in a city is OB Statistic because the data set of all adults in a city is a OC Statistic because the data set of all adults in a city is a

A card is drawn from a standard deck of 52 playing cards What is the probability that the card will be a diamond and not a face card Express your answer as a fraction or a decimal number rounded to four decimal places 4