# Confidence Interval for a Population Proportion

In 1992, the FAA conducted 86,991 pre-employment drug tests on job applicants who were to be engaged in safety and security-related jobs, and found that 1,143 were positive.

(a) Construct a 95 percent confidence interval for the population proportion of positive drug tests.

(b) Why is the normality assumption not a problem, despite the very small value of p?

https://brainmass.com/statistics/confidence-interval/confidence-interval-for-a-population-proportion-184458

#### Solution Summary

Step-by-step determination of the confidence interval. The other question is also answered.

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