The IQ Experiment

This case describes an IQ experiment in which 66 students, under the direction of their professor, used Excel to generate simulated IQs. The instructions were such that the generated IQs should have come from a normal distribution with a mean of 100 and standard deviation of 15. The sample average IQ, however, was 104.3. Students are asked to use their data-analysis skills to make sense of the results. The data set also contains gender (male or female) and fall section (A, B, C, D, or E) for each student, which allow for additional statistical analyses (tests of equality of means). Excerpt UVA-QA-0770 Aug. 31, 2011 The IQ Experiment In a classroom experiment, the professor instructed the class to enter the following function into Excel for the purpose of generating IQs from a normal distribution with a mean of 100 and a standard deviation of 15: =ROUND(NORM.INV(RAND(),100,15),0) “Instruments designed to measure real IQs,” the professor had explained, “were set up to produce IQs with exactly that distribution.” . . .