The variance in GMAT exam scores is 14,660 (the Graduate Management Admission Council's official website of the GMAT, June 17, 2016). A group of economics professors recently met at a conference to discuss the performance on the GMAT of undergraduate students majoring in economics. Some expected the variability in GMAT scores achieved by undergraduate students majoring in economics to be greater than the variability in GMAT scores of the general population of GMAT test takers. Others took the opposite view. The DATAfile EconGMAT contains GMAT scores for 51 randomly selected undergraduate students majoring in economics.
a. Compute the mean, variance, and standard deviation of the GMAT scores for the 51 randomly selected undergraduate students majoring in economics.
b. Develop hypotheses to test whether the sample data indicate that the variance in GMAT scores for undergraduate students majoring in economics differs from the general population of GMAT test takers.