5 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. 2 points (a) Calculate the r 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.) =Book Dependent Variable Estimated Slope Standard error Epuloulated p-value Differ from 0? Highest grade achieved 0.081 -0.027 0.009 0.008 References Reading grade equivalent 0.121 -0.070 0.018 0.000 Class standing 1.030 0.008 0.003 0.048 Absence from school 0.071 4.8 1.7 0.006 Grammatical reasoning 0.05 0.159 0.082 0.012 Vocabulary 0.108 -0.124 0.032 0.000 Hand-eye coordination 0.043 0.041 0.018 0.020 Reaction time 0.025 11.8 8.68 0.080 Minor antisocial behavior 0.025 -0.639 0.38 0.082 (b) It would be inappropriate to assume cause and effect without a better understanding of how the study was conducted. O Yes O No