The number of hours, h, it takes for a block of ice to melt varies inversely as the temperature, t. if it takes 2 hours for a square inch of ice to melt at 70 degrees, find the constant of proportionality

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.