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In: Statistics and Probability

The birth weights for two groups of babies were compared in a study. In one group...

The birth weights for two groups of babies were compared in a study. In one group the mothers took a zinc supplement during pregnancy. In another group, the mothers took a placebo. A sample of 33 babies in the zinc group had a mean birth weight of 3249 grams. A sample of 31 babies in the placebo group had a mean birth weight of 3143 grams. Assume that the population standard deviation for the zinc group is 870 grams, while the population standard deviation for the placebo group is 675 grams. Determine the 90%confidence interval for the true difference between the mean birth weights for "zinc" babies versus "placebo" babies.

Step 2 of 3 :  

Calculate the margin of error of a confidence interval for the difference between the two population means. Round your answer to six decimal places

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