Lead and Verbal IQ Scores Example 1 used measured performance IQ scores for three different blood lead levels. If we use the same three categories of blood lead levels with measured verbal IQ scores, we get the accompanying XLSTAT display. (The data are listed in Data Set 5 of Appendix: Data Sets.) Using a 0.05 significance level, test the claim that the three categories of blood lead level have the same mean verbal IQ score. Does exposure to lead appear to have an effect on verbal IQ scores?

XLSTAT Analysis of variance: Source DF Sum of squares Mean squares Model 2 142.259 71.130 Error 118 21441.460 181.707 Corrected Total 120 21583.719 F Pr F 0.391 0.677