A company has developed a new ink-jet cartridge for its printer that it believes has a longer life-time on average than the one currently being produced.To investigate its length of life,225 of the new cartridges were tested by counting the number of high-quality printed pages each was able to produce.The sample mean and standard deviation were determined to be 1511.4 pages and 35.7 pages,respectively.The historical average lifetime for cartridges produced by the current process is 1502.5 pages.What is the critical value for $\alpha$ = .05 to test the hypotheses.
A)1.645
B)-1.645
C)1.96
D)1.28
E)-1.96

Question

Quizplus · Accepted Answer

The critical value for F1F1F1S1F1F1F10 = .05 to test the hypotheses is 1.645. This is because the F-distribution is used to test the ratio of two variances, and the critical value for the F-distribution is the value that separates the upper 5% of the distribution from the lower 95%.

A Company Has Developed a New Ink-Jet Cartridge for Its α\alphaα

A Company Has Developed a New Ink-Jet Cartridge for Its $\alpha$