Original Problem: A researcher records the repair cost for 51 randomly selected dryers. A sample mean of $50.38 and sample standard deviation of $24.88 are subsequently computed. Determine the 99%...

Original Problem: A researcher records the repair cost for 51 randomly selected dryers. A sample mean of $50.38 and sample standard deviation of $24.88 are subsequently computed. Determine the 99% confidence interval for the mean repair cost for the dryers. Assume the population is normally distributed.

(a)  In the Original Problem, if I change confidence level to 80% instead of 99%, keep- ing all other factors the same, the length of the Confidence Interval or MarginError in the Original Problem increases or decreases, remains the same?

(b)  In the Original Problem, if I change n to 30 instead of 51, keeping all other factors the same, the length of the Confidence Interval or MarginError in the Original Problem increases or decreases or remains the same?