Question

In a recent year, the Better Business Bureau settled 75% of complaints they received. (Source: USA Today, March 2, 2009) You have been hired by the Bureau to investigate complaints this year involving computer stores. You plan to select a random sample of complaints to estimate the proportion of complaints the Bureau is able to settle. Assume the population proportion of complaints settled for the computer stores is the 0.75, as mentioned above. Suppose your sample size is 228. What is the probability that the sample proportion will be within 3 percentage points of the population proportion?

I want to how to get the answer using calculator

Answer 1

### by using Ti 84 function:

normalCdf(-1.05,1.05,0,1)

To use this function: press 2nd button--> VARS

Enter on normalCdf.

Specify lower =-1.05

Upper=1.05

My=0

Sigma=1

Then paste---> enter