Question: 1. If n = 200 and X = 50, construct a 95% confidence interval estimate of the population proportion.

2. If n = 400 and X = 25, construct a 99% confidence interval estimate of the population proportion.

3. The telephone company wants to estimate the proportion of households that would purchase an additional telephone line if it were made available at a substantially reduced installation cost. A random sample of 500 households is selected. The results indicate that 135 of the households would purchase the additional telephone line at a reduced installation cost.

a. Construct a 99% confidence interval estimate of the population proportion of households that would purchase the additional telephone line.

b. How would the manager in charge of promotional programs concerning residential customers use the results in (a)?