Carson and his family drove to disneyland. they started driving on thursday and then stopped for the night. on friday they drove twice as many miles as they had on thursday. on saturday, they drove 50 miles more than they had on friday. carson and his family live 650 miles from disneyland.

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.