Question

A researcher did a study looking at the effectiveness of different approaches to washing leafy green produce, with the goal of reducing risk for Escherichia coli (e coli) exposure in consumers. Farms were randomly assigned to either an enhanced washing regimen for three months, or to an industry-standard washing approach for the same amount of time. Periodically a member of a research team would visit each farm and obtain a sample of leafy greens for testing. The primary measure collected was the total number (count) of e-coli tainted samples collected from each farm over the three month period. There were 16 farms assigned randomly to each group. The distributions of e coli counts are below.

Typical washing: 6, 5, 9, 1, 0, 6, 2, 19, 3, 2, 1, 0, 1, 3, 6, 5

Enhanced washing: 2, 0, 3, 0, 0, 6, 3, 2, 0, 3, 0, 2, 2, 3, 1, 0

Compute the 95% Confidence Intervals for the each group, and then the CI 95% for the difference between the 2 groups. Using your CI 95% findings for the enhanced washing group, what is the margin of error? What is the standard error? Provide a brief narrative description for each CI you calculate.

Answer 1