Although kevin's psychology class is sometimes longer or shorter than usual, on the average each class is 50 minutes. if the lengths of these classes form a normal curve, which statistic would enable kevin to estimate the probability that any single class will last somewhere between 47 and 53 minutes?

Standard deviation

Explanation:

Standard deviation

The standard deviation is the measure that shows the deviation of particular data from the group.

The value of the standard deviation indicated the probability of the data is close to the mean

hence, lower standard deviation means the value is closer to the mean

Here, the mean is 50 minutes which is deviated 3 standard deviations from the given range i.e ( 50 - 3 = 47 and 50 + 3 = 53 )