A random sample of 70 printers discovered that 25 of them were being used and small businesses. Find the 95% confidence interval of the population of printers that are used in small

Answer 1

The 90% confidence interval is phat +/- z-critical * sqrt(phat*(1-phat)/sample size).

In this problem, phat = 25/70 = 0.357

sample size = 70

and z-critical for a 90% confidence interval is 1.645.

Plug in those number and you will be able to compute the confidence interval.