A random sample of n = 64 observations has a mean  = 29.1 and a standard deviation s = 3.9.
a. Give the point estimate of the population mean µ and find the margin of error for your estimate.
b. Find a 90% confidence interval for µ. What does "90% confident" mean?
c. Find a 90% lower confidence bound for the population mean µ. Why is this bound different from the lower confidence limit in part b?
d. How many observations do you need to estimate µ to within .5, with probability equal to .95?