A random sample of n measurements was selected from a population with unknown mean μ and standard deviation σ. Calculate a 99% confidence interval for μ for each of the following situations:
(a) n=85, x¯=23.8, s=3.75
≤μ≤
(b) n=120, x¯=62.7, s=4.52
≤μ≤
(c) n=80, x¯=50.6, s=2.67
≤μ≤
(d) n=85, x¯=91, s=2.73
≤μ≤