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

the sample standard deviation

Step-by-step explanation:

The statistic that would enable Dan to estimate the probability that any single class will last somewhere between 47 and 53 minutes is the sample standard deviation. If we have the mean and the standard deviation and we know that the lenghts of the classes form a normal curve, we can compute probabilities either with the empirical rule or using a table of probabilities from a book. The normal distribution is completely determined with the mean and the standard deviation.