A standardized third grade reading test, called the We Can Read Test, has a mean of 50 with a standard deviation of 10. A developmental psychologist conducts a study, where he assesses the reading ability of a random sample of 75 third graders using the We Can Read Test, and finds a mean of 53 with a standard deviation of 12.

11. Which of the following is a statistic?
a. 50
b. 53
c. 75
d. 10

A statistic is a numerical value calculated from a sample that describes some characteristic of that sample. In this case, the mean and standard deviation calculated from a random sample of 75 third graders are statistics.

Given the options:
a. 50 - This is the mean of the standardized reading test and not a statistic from the sample.
b. 53 - This is the mean calculated from the random sample of 75 third graders, which is a statistic.
c. 75 - This is the sample size, which is not a statistic describing the characteristics of the sample.
d. 10 - This is the standard deviation of the standardized reading test and not a statistic from the sample.

Therefore, the correct answer is b. 53.