Question

A survey about phone service has a margin of error of 5%. Out of 150 people surveyed, 103 said that they were pleased with their service. The phone company has 72,000 customers. What is the range of the number of people that are satisfied?

A. 46,968 to 51,912 customers
B. 46,986 to 51,192 customers
C. 46,698 to 51,291 customers
D. 48,696 to 52,191 customers

Answer 1

The range of the number of people that are satisfied is option A. 46,968 to 51,912 customers.

Explanation:

Hi, to solve this problem you need to calculate the total number of customers that are pleased with the service, based on the 150 people sample.

so:

(72,000 x 103 )÷150 = 49,440

The next step is to calculate the 5% margin of error of that result.

49,440 x 0.05= 2,472

Finally, to obtain the range you need to add and subtract the margin to the total number of customers that are pleased with the service.

49,440-2,472= 46,968

49,440 + 2,472=51,912

So, the range of the number of people that are satisfied is option A. 46,968 to 51,912 customers.