Question

The safety inspector in a large city wants to estimate the proportion of buildings in the city that are in violation of fire codes. A random sample of 35 buildings is chosen for inspection, and 3 of them are found to have fire code violations. Estimate the proportion of buildings in the city that have fire code violations, and find the uncertainty in the estimate.

Answer 1

Check Explanation.

Explanation:

The sample will be a representative of the entire build us in the city.

For a sample size 35, 3 have fire code violations, hence, the proportion of houses with fire code violations = (3/35) = 0.0857 = 8.57 %

The uncertainty in the estimate is given in the form of standard error.

Standard error = √[(p(1-p)/n]

n = sample size = 35, p = 0.0857, 1 - p = 0.9143

Standard error of the sample = √(0.0857×0.9143/35) = 0.1616

In terms of the population, (0.1616/35) = 0.00462

Proportion of buildings with fire code violations = (8.57 ± 0.462) %