Question 1010725
I'm not sure I understand the last part of this question.
I will assume the following.
mean=50
sd=3
The probability that 8 bags would contain fewer than 47 candies is the probability that 8 bags are 1 or more sd from the mean.   This is 16% of 50 bags, and the probability of anything in a normal distribution being more than -1 sd from the mean is 0.1584.  Therefore, 50 bags is a reasonable sample size to postulate.  Note, this is not the mean of the sample of bags, wherein a sample of 50 bags would not be expected to have a mean of 47 or fewer candies.