9. Inference about the difference between two means - Matched pairs experiment Are storebrand grocery items actually cheaper than their namebrand counterparts? A data set constructed by Michael McKay. a business statistics student at Fairfield University, will help you answerthis question. Michael randomly selected a sample of products and then collected data on the prices of the storebrand and the namebrand items sold at Groceries Plus (not its real name). For each selected grocery item in Michael's sample, the namebrand pricer the storebrand price, and the difference in those prices (name-brand minus store-brand} are shown in the DataView tool that follows. Data Set Groceries Sample Variables = 3 Observations = E Store-Brand and Name-Brand Prices for a Sample of Grocery Store Items Sample data collected by Michael McKay, business stats student, Fairfield University Observations Variable '0 Type 0' Form V Values 0' Missing 0' Dbserva ans 2- Name-Brand Price Quantitative Numeric E D Store-Brand Price Quantitative Numeric E 0 Difference in Price Quantitative Numeric E 0 Variable Variable Variable Correlation Correlation which of the following statements best describes how the data were collected and how they should be analyzed to make inferences about mg, the mean difference in price between namebrand and storebrand items sold at Groceries Plus? 0 Collected two independent samples of size 16 each; analyze two samples of 3 differences each O Collected two independent samples of size 8 each; analyze a single sample of 3 differences Q Collected a single sample of 8 pairs of data values; analyze a single sample of 16 differences '3 Collected a single sample of 8 pairs of data values; analyze a single sample of 8 differences Groceries Plus advertises that its store brand provides a savings to its customers of $1.25 per item on average. As a statistics consultant to the Better Business Bureau, you are asked to investigate the grocery store's claim using a hypothesis test. If there is sufcient statistical evidence to infer that the average savings per item is less than $1.25, the Better Business Bureau will take action to have Groceries Plus correct its advertising. The Better Business Bureau requests a 0.05 level of significance for your hypothesis test. (Hint: Define on = pmmmbmd mm letaanrand prim such that up > D ifon averagethe namebrand products cost more than the mean storebrand products and p3