# Statistics Testing - Customers favoring underground installation by ClassOf1

VIEWS: 46 PAGES: 4

• pg 1
```									              Sub: Statistics                                                                                  Topic: Testing

Question:
Test the proportion of customers favoring underground installation is more
than 60%.
ClassOf1 provides expert guidance to College, Graduate, and High school students on homework and assignment problems in
Math, Sciences, Finance, Marketing, Statistics, Economics, Engineering, and many other subjects.

A telephone company is trying to decide whether some new lines in a large community
should be installed underground. Because a small surcharge will be added to the phone bills
to pay for the extra installation costs the company has decided to survey customers and
proceed only if the survey strongly indicates that more than 60% of all customers favor
underground installation. In a random sample of 160 customers, 115 favor underground
installation in spite of the surcharge.

-Construct a 99% confidence interval for the proportion of customers favoring underground
installation.

Solution:
Given that, x : number of customers favoring underground installation = 115

And n : sample size = 160.

x    115
ˆ
So, p                   0.71875.

```
To top