Following are two confidence interval estimates of the mean of the cycles of failure of an automotive door latch mechanism (the test was conducted at an elevated stress level to accelerate failure).

3148.5 3250.25 3182.40 3216.35

(a) What is the value of the sample mean cycles to failure?

(b) The confidence level for one of theses CIs is 95% and for the other is 99%. Both CIs are calculated from the same sample data which is the 95% CI? Explain.