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 3232 babies in the zinc group had a mean birth weight of 32363236 grams. A sample of 3131 babies in the placebo group had a mean birth weight of 31833183 grams. Assume that the population standard deviation for the zinc group is 775775 grams, while the population standard deviation for the placebo group is 559559 grams. Determine the 90%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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