Simple regression was employed to establish the effects of childhood exposure to lead. The effective sample size was about 122 subjects. The independent variable was the level of dentin lead (parts per million). Below are regressions using various dependent variables. (a) Calculate the t statistic for each slope, at significance level = 0.01. (Negative values should be indicated by a minus sign. Round your answers to 2 decimal places.) Dependent Variable R2 Estimated Slope Standard error tcalculated p-value Differ from 0? Highest grade achieved 0.061 -0.027 0.009 0.008 Yes Reading grade equivalent 0. 121 -0.070 0.018 0.000 Yes Class standing 0.039 -0.006 0.003 0.048 No Absence from school 0.071 4.8 1.7 0.006 Yes Grammatical reasoning 0.051 0.159 0.062 0.012 No Vocabulary 0.108 -0.124 0.032 0.000 Yes Hand-eye coordination 0.043 0.041 0.018 0.020 No Reaction time 0.025 11.8 6.66 0.080 No Minor antisocial behavior 0.025 -0.639 0.36 0.082 No