Question

Suppose dice were rolled 300 times. Find the mean and standard deviation for a sum of five.

Answer 1

the mean is 33.3 and the standard deviation is 5.44. I just don't know how to get those answers :/

Answer 2

What a strangely-worded question. I think it means, "Calculate the mean and standard deviation of the Random Variable X that represents the number of 5s achieved in 300 rolls of a fair die." In other words, you roll a die 300 times, how many 5s can you expect?

A fair die has six sides. P(getting a 5 on 1 roll) = 1/6 -- You must believe this.