Question

At Abraham Lincoln High School an achievement test is used for college placement. Counselors selected a simple random sample of 30 students from the school and scored their tests by hand before sending them in for computer processing. For this sample, top enclose x equals 525 comma space s equals 25 . Construct a 99% confidence interval for mu, the population mean score for Abraham Lincoln High School. Round your answer to one decimal place.

Answer 1

Solution :

t _/2,df = 2.756

Margin of error = E = t_/2,df * (s /n)

= 2.756 * (25 / 30)

Margin of error = E = 12.6

The 99% confidence interval estimate of the population mean is,

- E < < + E

525 - 12.6 < < 525 + 12.6

512.4 < < 537.6

(512.4 , 537.6)