A new grug had the potency advertised at 75%. Given the following smaple data:
N=25
X bar = 76.6%
S=1%
a) Check manufacturer's claim of the 775% potency at alpha = .05 (one tail)
b) Make a 90% confidence interval
c) If the desired error of the estimation is less than 0.1% with 99% confidence, what should the sample size be?