Two high speed ferries leave at the same time from a city to go to the same island. The first ferry, the cat, travels 33 miles Per hour. The second ferry, the bird, travels at 20 miles per hour. In how many hours will the two ferries be 13 miles apart?

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.