Sam and annika ride their bikes to school. sam rides his bike (k )kilometers. annika rides her bike two less than four times as many kilometers at sam rides.
explain why sam must ride his bike more than 1/2 kilometer to school

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.