A Random Sample of 79 Companies from the Forbes 500

Multiple Choice

A random sample of 79 companies from the Forbes 500 list (which actually consists of nearly 800 companies) was selected,and the relationship between sales (in hundreds of thousands of dollars) and profits (in hundreds of thousands of dollars) was investigated by regression.The following results were obtained from statistical software. Suppose the researchers conducting this study wish to estimate the profits (in hundreds of thousands of dollars) for companies that had sales (in hundreds of thousands of dollars) of 500.The following results were obtained from statistical software. If the researchers wish to estimate the mean profits for all companies that had sales of 500,what would be a 95% confidence interval for the mean profits?

A) (-1066.4,805.6)
B) (-248.5,-12.3)
C) -130.4 ± 59.3
D) 500 ± 59.3