Given the following sales data for weekly gross receipts of a random sample of 25 restaurants in an international fast food chain (in $1000): 39 38 54 43 37 48 52 9 34 47 10 48 43 48 58 22 14 21 65 18 53 63 41 25 36
a)MINITAB Output. Enter these data into a MINITAB worksheet all in one column. Use Sales as your header. Select Stat > Basic Statistics > 1-sample t... Complete the dialog in order to obtain a 95 percent confidence interval for the average weekly sales of all 8,000 plus restaurants in this chain.
b) Based on your interval, do you believe you have strong evidence to indicate that the average weekly sales of restaurants in this chain are significantly higher than $22,000? Explain.