Betty’s bite-size candies are packaged in bags. the number of candies per bag is normally distributed, with a mean of 50 candies and a standard deviation of 3. at a quality control checkpoint, a sample of bags is checked, and 4 bags contain fewer than 47 candies. how many bags were probably taken as samples?

We first find the probability of finding a bag containing fewer than 47 candies. 
Solving for the z score of x =47:
z = (x-μ)/σ = (47-50)/3 = -1
Using a z table, we find that the probability of z=-1 is 0.1587.

Therefore, if 4 bags are 0.1587 of the sample size, then
4 = 0.1587n
n = 4/0.1587
n = 25.20 ≈ 25 bags were probably taken as samples.

Hnmmmn not sure