Question

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 31 babies in the zinc group had a mean birth weight of 3223 grams. A sample of 31 babies in the placebo group had a mean birth weight of 3222 grams. Assume that the population standard deviation for the zinc group is 681grams, while the population standard deviation for the placebo group is 844  grams. Determine the 80% confidence interval for the true difference between the mean birth weights for "zinc" babies versus "placebo" babies.

Step 1 of 3:

Find the point estimate for the true difference between the population means.

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.

Step 3 of 3:

Construct the 80% confidence interval. Round your answers to the nearest whole number.

Answer 1