Question

A sample of 1500 computer chips revealed that 55% of the chips do not fail in the first 1000 hours of their use. The company's promotional literature states that 53% of the chips do not fail in the first 1000 hours of their use. The quality control manager wants to test the claim that the actual percentage that do not fail is different from the stated percentage. Find the value of the test statistic. Round your answer to two decimal places.

Answer 1

Excel add-in (Mega Stat) procedure Step 1: In EXCEL, Select Add-Ins> Mega Stat> Hypothesis Tests Step 2: Choose Proportion vs. Hypothesized Value Step 3: Choose Data Input Step 4: In Observed, enter the value 0.55 under p and enter the value 1500 under n Step 5: In Hypothesized, enter the value 0.53 under p Step 6: Enter 0 Under Hypothesized difference Step 7: Choose not equal in alternative Step 8: Click OK. Excel add-in (Mega Stat) output Hypothesis test for proportion vs hypothesized value Observed Hypothesized 0.55 0.53 p (as decimal) 825/1500795/1500 p (as fraction) 825 1500 795. X 1500 n 0.0129 std. error 1.55 Z 1207 p-value (two-tailed) The value of the test statistic is z -1.55

The critical values are Zeit +1.96 Conclusion: Since z1.55)1.96), then do not reject the null hypothesis. (-1.96), then do not reject the null hypothesis. Therefore, 53% of the chips do not fail in the first 1000 hours of their use.