39. One gallon fills about 231 in A right cylindrical carton is 12 in. tall and holds 9 gallons when full. Find the radius of the carton to the nearest tenth of an inch.
A. 0.5 in
b. 7.4 in.
c. 37.7 in.
d. 55. lin

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.