Recently, a university surveyed recent graduates of the English Department for their starting salaries. Four hundred graduates returned the survey. The average salary was $25,000. The population standard deviation is known to be $2,500.
What is the 95% confidence interval for the mean salary of all graduates from the English
Department?
A) 22,500, $27,500
B) 24,755, $25,245
C) 24,988, $25,012
D) 24,600, $25,600

Question

Quizplus · Accepted Answer

The 95% confidence interval is calculated using the formula: mean ± (Z * (σ/√n)). Here, the mean is $25,000, Z is 1.96 for 95% confidence, σ is $2,500, and n is 400. This results in the interval $24,755 to $25,245.

Recently, a University Surveyed Recent Graduates of the English Department