Use the sample information x-bar = 37, = 5, n = 15 to calculate the following confidence intervals for assuming the sample is from

Use the sample information x-bar = 37, σ = 5, n = 15 to calculate the following confidence intervals for assuming the sample is from a normal population:
(a) 90 percent confidence;
(b) 95 percent confidence;
(c) 99 percent confidence.
(d) Describe how the intervals change as you increase the confidence level.