A cellphone provider has the business objective of wanting to estimate the proportion of subscribers who would upgrade to a new cellphone with improved features if it were made available at a substantially reduced cost. Data are collected from a random sample of 500 subscribers. The results indicate that 135 of the subscribers would upgrade to a new cell-phone at a reduced cost.
a. Construct a 99% confidence interval estimate for the population proportion of subscribers that would upgrade to a new cell-phone at a reduced cost.
b. How would the manager in charge of promotional programs use the results in (a)?