Author: Anonymous

The following data shows the yield, in bushels per acre, categorized according to 3 varieties of corn and 3 different soil conditions (i.e., plots). Perform the appropriate ANOVA and answer the following questions.Does the analysis consider a possible interaction between the factors (corn varieties and plots) that needs to be examined? [inter] (enter yes or no)If so, what is the p-value associated with the interaction? [pint] (round to 3 decimals)Is the interaction statistically significant at alpha=0.05? [intsig] (enter yes or no)What is the is the p-value for the difference in the average yield between the varieties of corn? [pcorn] (round to 3 decimals)At an alpha of 0.05, can we say the difference between the varieties of corn is meaningful and significant? [sigcorn] (enter yes, no, or na if the question cannot be answered)What is the p-value for the difference in average yield between the plots? [pplot] (round to 3 decimals)At an alpha of 0.05, can we say the difference between plots is meaningful and significant? [sigplot] (enter yes, no, or na if the question cannot be answered)   Plot 1 Plot 2 Plot 3 Variety 1 156 162 155 Variety 1 167 160 161 Variety 1 170 169 158 Variety 1 162 168 165 Variety 2 172 179 171 Variety 2 176 186 172 Variety 2 166 160 175 Variety 2 179 176 180 Variety 3 175 178 179 Variety 3 157 170 175 Variety 3 179 172 180 Variety 3 178 174 179

The lifetime prevalence of APD in the prison system is less than that of the general population. 

An independent variable (x) is used to predict a dependent variable (y). Answer the questions for each scenario based on the data in the table below. Each scenario shows the sample size (n), the correlation (r), the regression equation (y=mx+b), and an alpha value. Hint: Use Table A-6 or compare the critical value with the test statistic to determine whether or not the correlation is significant and the regression valid.For scenario 1   Is the correlation significant? [sig1] (answer “yes” or “no”)   Given x=2, what is the best prediction of the value of y? [y1] (round to 1 decimal)For scenario 2   Is the correlation significant? [sig2] (answer “yes” or “no”)   Given x=2, what is the best prediction of the value of y? [y2] (round to 1 decimal)For scenario 3   Is the correlation significant? [sig3] (answer “yes” or “no”)   Given x=4, what is the best prediction of the value of y? [y3] (round to 1 decimal)   n r y-bar regression alpha Scenario 1 12 0.50 9.3 y=3x+3 0.05 Scenario 2 10 0.70 6.5 y=2x+3 0.01 Scenario 3 40 0.50 8.7 y=2x+1 0.20

The following data shows human body temperatures from random samples of three different age groups. Perform an ANOVA and answer the following questions.What is the average body temperature for 30+ year olds? [avg30] (round to 2 decimals)What is the variance in body temperature for 18-20 year olds? [var18] (round to 2 decimals)What is the p-value for this ANOVA? [pval] (note: round to 3 decimals)At an alpha of 0.05, is there a significant difference in mean body temperatures between the age groups? [sig] (enter yes or no)Without further analysis, is it possible to say for sure which specific group is, or is not, different from which other specific group(s)? [diff] (enter yes or no) 18-20yrs 21-29yrs 30+yrs 98.3 99.9 97.8 98.6 98.7 98.3 98.1 99.0 97.0 98.7 98.2 97.4 97.5 98.1 96.9

The table below shows data from a study comparing what people said their annual income was (in thousands of dollars), as opposed to what they reported on their tax return. Assuming alpha=0.01, use this data to test the claim that people say they have a greater annual income than what they actually report on their taxes. Said 50 48 43 39 35 33 28 for Tax 48 48 40 37 32 34 27 What is the mean of the difference in incomes (d-bar)? [dbar] (round to 1 decimal)What is the standard deviation of the difference (s-d)? [sd] (round to 2 decimals)What is the left critical value? [cvL] (round to 2 decimals – enter “na” if there is none)What is the right critical value? [cvR] (round to 2 decimals – enter “na” if there is none)What is the value of the test statistic? [ts] (round to 2 decimals)What is the result of the hypothesis test? [result] (enter “reject H0” or “fail to reject H0”)Is the claim supported? [support] (enter “yes” or “no”)

In a comparison of customer satisfaction, a researcher collects data showing that for Company B, among 550 randomly selected customers 92.0% were satisfied. For Company A, among 450 randomly selected customers 94.0% were satisfied. Assuming alpha=0.20, answer the following questions as you test the claim that Company B has at least as high a proportion of satisfied customers as does Company A.The value of p-bar (pooled p) = [pbar] (round to 3 decimals)The left critical value = [left] (round to 2 decimals – if there is no left value, enter “na”)The right critical value = [right] (round to 2 decimals – if there is no right value, enter “na”)The test statistic = [ts] (round to 2 decimals)Is the claim supported? [support] (enter “yes” or “no”)

A large buyer of transportation services wants to compare the standard deviation in delivery lead times between standard UPS and Fedex shipments.100 UPS shipments are randomly selected, and an analysis indicates a standard deviation of 4.2 days.150 Fedex shipments are randomly selected, and an analysis indicates a standard deviation of 3.3 days.Using this information, answer the following questions and test the claim that the standard deviation in delivery lead times for UPS is greater than that of Fedex, assuming alpha=0.01.(Hint: make sure you designate the sample with the larger variance as sample1 and the other as sample2 in your calculations. We are also always only interested in the right F critical value)What is the value of the F critical value? [Fcv] (round to 2 decimals)What is the value of the F test statistic? [Fts] (round to 2 decimals)What is the result of the hypothesis test? [result] (enter “reject H0” or “fail to reject H0”)Is the claim supported? [support] (enter “yes” or “no”)

Various studies are conducted to compare the rates of addiction to prescription drugs across various populations. One such study compares the proportion of Arizona vs Utah residents who are addicted to prescription drugs. Data collected from 1600 randomly selected Arizona residents indicates that 169 are addicted to prescription drugs. Data is also collected from 1300 randomly selected Utah residents, and shows that 98 are addicted to prescription drugs. . Use this data, assuming alpha=0.02, to answer the following questions and test the claim that the proportion of Arizona residents addicted to prescription drugs is the same as that of Utah residents.The value of p-bar (pooled p) = [pbar] (round to 3 decimals)The left critical value = [left] (round to 2 decimals – if there is no left value, enter “na”)The right critical value = [right] (round to 2 decimals – if there is no right value, enter “na”)The test statistic = [ts] (round to 2 decimals)What is the result of the hypothesis test? [result] (enter “reject H0” or “fail to reject H0”)

Tests of the flammability of children’s sleepwear were conducted independently by three different labs. Results are shown in the table below. Perform an ANOVA and answer the following questions.What is the average flammability rating reported by Lab#2? [avglab2] (round to 2 decimals)What is the variance in flammability rating for Lab#1? [varlab1] (round to 2 decimals)What is the p-value for this ANOVA? [pval] (note: round to 3 decimals)At an alpha of 0.05, is there a significant difference in the mean of flammability between the labs? [sig] (enter yes or no) Lab#1 Lab#2 Lab#3 2.5 4.3 3.0 3.0 3.4 3.2 2.9 4.1 2.4 3.0 3.4 3.3 2.8 3.7 2.2 2.6 4.1 2.6 2.6 3.5 1.9 2.6 3.9   3.7 3.4   3.3    

A weight loss product claims that, after a week of using their product, a person’s weight will go down by more 6 pounds. To test this claim, 7 people are randomly selected who use the weight loss product for a week. Before and after weights are  shown in the table below. Use this data to answer the following questions and to test the claim. Assume alpha=0.03. Before 195 234 276 310 179 263 205 After 188 227 270 298 173 256 199 What is the mean of the difference in weight (d-bar)? [dbar] (round to 1 decimal)What is the standard deviation of the difference in weight (s-d)? [sd] (round to 2 decimals)What is the left critical value? [cvL] (round to 2 decimals – enter “na” if there is none)What is the right critical value? [cvR] (round to 2 decimals – enter “na” if there is none)What is the value of the test statistic? [ts] (round to 2 decimals)What is the result of the hypothesis test? [result] (enter “reject H0” or “fail to reject H0”)Is the claim supported? [support] (enter “yes” or “no”)