he telephone company wants to estimate ~’J 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 ind

Question No 8.28 8.28 The telephone company wants to estimate

~’J 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 for the

population proportion of households that would purch~l:-;e

the additional telephone line.

b. How would the manager in charge ofpromotional programs

concerning residential customers use the results in (a)?