Question 687:
1Answer:
No answer provided yet.
A. Since we are told that two different groups of customers were used, that makes this an independent sample test, and the 1st output correct.
B From looking at the output, we see the difference in prices was -7.46, however this difference was not statistically significant since the p-value is above .05. We could not conclude from this data that there is a difference in average prices.
C. The procedure used here, an independent sample t-test on the means from a random sample is valid. The t-test is valid since we are estimating the standard deviations of each grocery store's family cost. The independent t-test is valid since different samples were used at each store. An alternative approach would be to randomly select 100 of the same items at each store, then compare those prices.