In a study of online vs. in-person statistics courses, a researcher wishes to test the claim that the average student grade in online stats courses is higher than than average student grade in in-person stats courses. To test this claim 60 online student’s grades are randomly selected, with an average of 86.8 and a standard deviation of 5.25. In addition, 70 in-person student’s grades are randomly selected, with an average of 85.0 and a standard deviation of 6.37. Based on this data, and using an alpha=0.05, answer the following questions.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)The result of the hypothesis test is [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 A, among 200 randomly selected customers 95.0% were satisfied. For Company B, among 300 randomly selected customers 88.0% were satisfied. Assuming alpha=0.01, answer the following questions as you test the claim that Company A has a higher proportion of satisfied customers than does Company B.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”)

Using the data shown in the table below, answer the following questions.What is the correlation between X1 and Y? [corX1Y] (round to 2 decimals)What is the correlation betwen X2 and Y? [corX2Y] (round to 2 decimals)What is the correlation betwen X1 and X2? [corX1X2] (round to 2 decimals)How much of the variation in Y is explained by a regression model that uses only X1 to predict Y? [r2X1] (round to 2 decimals)How much of the variation in Y is explained by a regression model that uses only X2 to predict Y? [r2X2] (round to 2 decimals)How much of the variation in Y is explained by a regression model that uses both X1 and X2 to predict Y (hint: R-squared)? [r2X1X2] (round to 2 decimals)How much of the variation in Y is explained by a regression model that uses both X1 and X2 to predict Y, taking into account the correlation between X1 and X2 (hint: Adjusted R-squared)? [adjr2X1X2] (round to 2 decimals)At what level is the multiple regression statistically significant (i.e.,Sig.F)? [sig] (round to 2 decimals)In the multiple regression model, what is the coefficient of X1 in the regression equation? [X1cof] (round to 2 decimals)In the multiple regression model, what is the coefficient of X2 in the regression equation? [X2cof] (round to 2 decimals)What is the intercept in multiple regression equation? [int] (round to 2 decimals)Given X1=100 and X2=100, what would be the predicted value of Y? [esty] (round to just 1 decimal) Y X1 X2 106.5 125.1 110.2 104.2 109.6 107.4 103.1 103.3 103.3 99.2 95.3 101.2 98.3 104.1 100.1 98.1 102.5 96.6 95.9 89.5 93.2 96.2 83.5 101.9 96.1 75.8 98.6 99.2 73.6 98.1 98.7 87.8 102.8 100.5 95.5 101.6 100.3 106.7 102.3 100.2 102.1 106.7 101.2 99.4 104.7 99.9 98.7 106.1 101.3 97.4 103.2 97.5 95.6 109.3 95.8 96.5 109.2 95.1 86.3 107.4

Support groups such as AA are grounded in a psychological model of therapy.

Co-occurring disorders do not generally pose impediments to successful substance abuse treatment. 

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 1 153 164 155 Variety 1 162 162 161 Variety 1 167 171 158 Variety 1 159 170 165 Variety 2 169 181 171 Variety 2 173 188 172 Variety 2 166 164 175 Variety 2 175 178 180 Variety 3 172 180 179 Variety 3 157 173 175 Variety 3 173 175 180 Variety 3 174 176 179

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 99.0 99.9 98.2 98.8 98.3 98.5 98.5 99.2 98.2 99.6 98.4 98.3 98.8 98.1 98.3

Various studies are conducted to compare the rates of addiction to prescription drugs across various populations. One such study compares the proportion of Utah vs Arizona residents who are addicted to prescription drugs. Data is collected from 1500 randomly selected Utah residents, and shows that 108 are addicted to prescription drugs. Data collected from 1800 randomly selected Arizona residents indicates that 101 are addicted to prescription drugs. Use this data, assuming alpha=0.05, to answer the following questions and test the claim that the proportion of Utah residents addicted to prescription drugs is greater than the proportion of Arizona residents who are addicted to prescription drugs.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”)

In a study of in-person vs. online statistics courses, a researcher wishes to test the claim that the average student grade in in-person stats courses is at least as high as the average student grade in online stats courses. To test this claim 70 in-person student’s grades are randomly selected, with an average of 83.7 and a standard deviation of 7.98. In addition, 60 online student’s grades are randomly selected, with an average of 85.0 and a standard deviation of 8.83. Based on this data, and using an alpha=0.20, answer the following questions.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)The result of the hypothesis test is [result] (enter “reject H0” or “fail to reject H0”)Is the claim supported? [support] (enter “yes” or “no”)

A consumer research firm conducts a study to compare the cleaning power of 3 different laundry detergents and 4 different water temperatures. Results are shown in the table below, with a higher number representing greater cleaning power. Perform a two-factor ANOVA and answer the following questions.What water temperature has the highest average cleaning power? [highwater] (enter the temp name, e.g. cool)What water temperature has the lowest average cleaning power? [lowwater] (enter the temp name, e.g. cool)What is the p-value in the ANOVA for the difference in the average  water temperatures? [pvalwater] (round to 3 decimals)At an alpha of 0.05, is there a significant difference in the average water temperatures? [sigtemp] (enter yes or no)What is the p-value for the difference in the average cleaning power of the detergents? [pvaldet] (round to 3 decimals)At an alpha of 0.05, is there a significant difference in average cleaning power of the different detergents? [sigdet] (enter yes or no) Det A Det B Det C Cold 27 20 19 Cool 24 16 18 Warm 29 24 25 Hot 17 13 20