Question: Given below is the STATA output looking at the overall differences between three categories of lead exposure and the mean IQ for children. The exposure groups are defined as: 1 = control group, 2 = currently exposed & 3 = previously exposed.
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Analysis of variance
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source
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ss
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df
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MS
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F
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Prob>F
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Between groups
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1600.097
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2
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800.048437
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4.05
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0.0199
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Within groups
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23919.1
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121
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197.678485
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Total
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25519.19
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123
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207.473118
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Bartlett's test for equal variances : chi2(2) = 7.4930 Prob > chi2 = 0.024
Comparison of full scale iq by exposure group ( bonferroni)
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Row mean- col Mean
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1
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2
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2
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-0.64189
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1
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3
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8.64657
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9.28846
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0.024
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0.064
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[A] Justify the conclusion by describing the relevant information from the output.
[B] What do you conclude about the IQ of children and their exposure status?