Abicyclist started riding at 8: 00a. m. the diagram below shows the distance the bicyclist had traveled at different times. what was the bicyclists average rate of speed in miles per hour? 8: 00a. m (@ 4.5miles) to 8: 15a. m. (@ 7.5 miles) to 8: 45a. m.

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.