SOLUTION: My question:Among coffee drinkers, men drank a mean of 3.2 cups per day with a standard deviation of 0.8 cups assume the # cups is normal distribution. a. What proportion drank 2

Algebra ->  Probability-and-statistics -> SOLUTION: My question:Among coffee drinkers, men drank a mean of 3.2 cups per day with a standard deviation of 0.8 cups assume the # cups is normal distribution. a. What proportion drank 2      Log On


   



Question 910746: My question:Among coffee drinkers, men drank a mean of 3.2 cups per day with a standard deviation of 0.8 cups assume the # cups is normal distribution.
a. What proportion drank 2 cups or more?
b. What proportion drank no more than 4 cups per day?
c. If 5% of coffee drinkers are considered heavy coffee drinkers what is the minimum number of cups consumed by a heavy coffee drinker?
d.If a sample of 20 men is selected what is the probability that the mean number of cups per day is greater than 3?
I am working on this problem and want to make sure I am on the right track. Thank you!

Answer by ewatrrr(24785) About Me  (Show Source):
You can put this solution on YOUR website!
mean = 3.2, sd = .8
a) P(x ≥ 2) = 1 - normalcdf(2, 100, 3.2,.8).... 100 a placehoder
b) )(x ≤ 4) = normalcdf(-100, 4, 3.2,.8)
c) .8invNorm(.95) + 3.5 =X, number of cups consumed by a heavy coffee drinker
d) s = .8/sqrt(20)
P(x>3) = 1 - normalcdf(-100,3,3.2,s)