Which is the midpoint of the line segment with endpoints (1, 2) and (7,8)? A. (6, 6)
B. (3,3)
C. (4,3)
D. (4,4)
E. (4,5)

Arandom sample of n = 25 observations is taken from a n(µ, σ ) population. a 95% confidence interval for µ was calculated to be (42.16, 57.84). the researcher feels that this interval is too wide. you want to reduce the interval to a width at most 12 units. a) for a confidence level of 95%, calculate the smallest sample size needed. b) for a sample size fixed at n = 25, calculate the largest confidence level 100(1 − α)% needed.