In a study of birth order and intelligence, IQ tests were given to 18- and 19-year-old men to estimate the size of the difference, if any, between the mean IQs of firstborn sons and secondborn sons.

The following data for 10 firstborn sons and 10 secondborn sons are consistent with the means and standard deviations reported in the article. Assume that the samples come from normal populations.

Can you conclude that the standard deviation of IQ differs between firstborn and secondborn sons? Use the α = 0.05 level.

Firstborn 104 82 102 96 129 89 114 107 103 107 89 Secondborn 103 103 91 113 102 103 92 90 114 113