Question

A random sample of 200 computer chips is obtained from a factory and 4% are found to be defective. Construct and interpret a 95% confidence interval for the proportion of all computer chips from the factory that are defective. Use Example T.9 on page 501 as a guide and format your answer like the example. (Note: Be sure that you are clear about what x, n, and p-hat are in this problem before you just enter numbers into Excel.) Write your sentences in cell A9. (The function in Excel 2007 is NORMSINV, but you will need to read about the NORMSINV function and think about what the first parameter will need to be to do this problem correctly.)

Need: inputting data correctly, constructing the correct confidence interval, correctly stating and interpreting the confidence interval, and correctly answering the question about the running shoe company’s claim in excel.

Answer 1

Solution :

We are 95% confident that the proportion of all computer chips from that factory that are defective is between 0.013 and 0.067.