You are the owner of three local sandwich shops. Recently you've received complaints from customers that their "footlong" sub sandwiches were less than 12 inches long. As a measure of quality...

 problem: customers are complaining about the sandwich length Interpret the results: **please just interpret the last three**

Extracted text: You are the owner of three local sandwich shops. Recently you've received complaints from customers that their "footlong" sub sandwiches were less than 12 inches long. As a measure of quality assurance, data was collected on all footlong sub sandwiches made over the period of an hour at each store. Determined which, if any, of your stores are making sub sandwiches that are significantly shorter than 12 inches. You will conduct three t-tests, one for each store. You want to be 95% confident in your results. (Note. This case is inspired by reality. Search the internet for 'claims over footlong sub' for a historical perspective and how a company used statistics to insure consistent quality.) Sandwich Measurements Statistics Store 1 Store 2 Store 3 Store 1 Store 2 Store 3 Sample Size Mean (length) Variance 8.8 9.1 9.0 18 8. 11.4 11.6 12.5 11.00 11.00 12.10 13.4 13.4 15.1 2.31 2.25 11,3 11.4 14.3 Standard Deviation 1.52 1.50 2.18 10.1 10.3 10.8 12.4 Hypothesized Mean (M) Difference in Means (x - M) 12,4 13.8 12 12 12 10.4 10.6 11.2 |-1.00 -1.00 0.10 8.9 9.2 9.1 Standard Error 0.36 0.53 0.49 10.4 11.1 T-Statistic -2.79 -1.89 0.21 11.8 14.0 Degrees of Freedom 12.8 14.3 9.3 8.7 P-value P(T=t) two-tail* 50 12.6 13.7 *Remember that the T.DIST.2T() function requires the t-statistic 11.7 argument to be an absolute value, not a negative value, or an error 12.9 7 11.8 will occur. 13.0 8 9.7 10.2 -9 12.6 14.1 8.6 8.6 Interpret the Results 1. What is the null hypothesis for these tests? 2. What is the alternative hypothesis for these tests? 3. Given the desired confidence level, what alpha should be used? 31 14.6 HO: µ = 12 H1: u12 32 11.0 33 34 35 4. Can you say with 95% confidence that Store 1 is producing sub sandwiches with an average length that is less than 12 inches? 5. Can you say with 95% confidence that Store 2 is producing sub sandwiches with an average length that is less than 12 inches? 6. Can you say with 95% confidence that Store 3 is producing sub sandwiches with an average length that is less than 12 inches? a=0.05 [select] 36 37 [select] 38 39 [select) 40 41 42 43 44 45