Simple regression was employed to establish the effects ofchildhood exposure to lead. The effective sample size was about 122subjects. The independent variable was the level of dentin lead(parts per million). Below are regressions using various dependentvariables.
(a) Calculate the t statistic for each slope. Fromthe p-values, which slopes differ from zero at α = .01?(Round your answers to 2 decimal places. Negative valuesshould be indicated by a minus sign.)
| Dependent Variable | R2 | Estimated Slope | Std Error | tcalculated | p-value | | Differ from 0? |
| Highest grade achieved | | 0.050 | | | -0.029 | | | 0.010 | | | | | | .004 | | | (Click to select)  No  Yes |
| Reading grade equivalent | | 0.126 | | | -0.093 | | | 0.022 | | | | | | .000 | | | (Click to select)  Yes  No |
| Class standing | | 0.078 | | | -0.005 | | | 0.002 | | | | | | .014 | | | (Click to select)  Yes  No |
| Absence from school | | 0.073 | | | 4.700 | | | 1.620 | | | | | | .004 | | | (Click to select)  No  Yes |
| Grammatical reasoning | | 0.090 | | | 0.132 | | | 0.070 | | | | | | .062 | | | (Click to select)  No  Yes |
| Vocabulary | | 0.119 | | | -0.196 | | | 0.002 | | | | | | .000 | | | (Click to select)  Yes  No |
| Hand-eye coordination | | 0.035 | | | 0.060 | | | 0.027 | | | | | | .028 | | | (Click to select)  Yes  No |
| Reaction time | | 0.016 | | | 9.300 | | | 3.560 | | | | | | .010 | | | (Click to select)  No  Yes |
| Minor antisocial behavior | | 0.037 | | | -0.819 | | | 0.579 | | | | | | .160 | | | (Click to select)  No  Yes |
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(b) It would be inappropriate to assume cause andeffect without a better understanding of how the study wasconducted.
