Mean which is also called average is that representative value for a given set of data. Given that the mean is 30, it is the best value that represents the set of values.
Standard deviation tells us how far a given value is from the mean. It can be closer or farther. Given that the standard deviation is 2, the closest observations would fall within
30 - 2 and 30 + 2. This makes it between 28 and 32. 24 and 36 are 3 standard deviations from the mean. All observations would almost fall within this range. Thus, the answer is True