In Exercise? ?use analysis of variance for the indicated test. Lead and Full 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 the ?full? IQ scores, we get the accompanying Excel display. (The data are listed in Data Set 5 of Appendix B.) Using a 0.05 significance level, test the claim that the three categories of blood lead level have the same mean full IQ score. Does it appear that exposure to lead has an effect on full IQ scores? Example 1? Lead and Performance IQ Scores
Solution 6BSC Step 1 The given problem explain about lead and full IQ scores. From the given problem measured performance IQ scores for three different blood lead levels.then we use the same three categories of blood lead levels with the full IQ scores. In case,the three categories of null hypothesis have same mean full IQ scores or = = . 1 2 3 Here, e know that the significance level of =0.05 Then the P-value = 0.10439 (from the excel table) Hence the P-value > the significance level of =0.05 Therefore 0.10439 > 0.05 So,we cannot reject the null hypothesis of (equal means) = = . 1 2 3 Hence we can accept the null hypothesis of (equal means) = 1 . 2 3 From the given information we can conclude that we do not have sufficient evidence to conclude that lead exposure has an effect on full IQ scores. Here the three populations of means may be different but that difference may be simply due to random sampling error. Therefore, we fail to reject or accept that low, medium and high blood lead levels have same level of full IQ scores.