A new cookbook is becoming popular. The local bookstore ordered 10 copies in January, 20
copies in February, 80 copies in March, and 480 copies in April. What kind of sequence is this?
arithmetic
geometric
both
neither

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.