Question

The service life of a battery used in a cardiac pacemaker is assumed to be normally distributed. A sample of twelve batteries is subjected to an accelerated life test by running them continuously at an elevated temperature until failure, and the following lifetimes (in hours) are obtained: 26.7, 26.8, 25.8, 24.7, 24.6, 27.4, 25.5, 27.2, 27.5, 24.9, 26.9, and 25.5. Test the hypothesis that the mean battery life exceeds 25 hours.

A.) State the null and alternative hypothesis.

B.) Compute the test statistics.

C.) Compute the P-value.

D.) State a conclusion

E.) Construct a 95% two-sided confidence interval on mean life in the accelerated test.

Answer 1