A simple random sample of 47 adults is obtained and each person's red blood cell count (in cells per microliter) is measured. The sample mean is 4.44. The population standard deviation for red blood cells counts is 0.56. Assume all conditions are satisfied for inference to all adults.
a. Construct a 99% confidence interval for ux, the mean red blood cell count for all adults. Round 2 decimal places
upper bound:
lower bound:
b. Suppose the level of confidence decreases. What would happen to the width of the confidence interval?
Stay the same, increase or decrease?