In: Statistics and Probability
Salaries of 4949 college graduates who took a statistics course in college have a mean,
x̄, of $62,800. Assuming a standard deviation, σ, 11,139 construct a 99% confidence interval for estimating the population mean μ
Solution :
Given that,
Sample size = n = 4949
Z
/2
= Z0.005 = 2.576
Margin of error = E = Z
/2*
(
/n)  
= 2.576* (11139 / 
4949)
Margin of error = E = 407.9
At 99% confidence interval estimate of the population mean is,
- E < 
 < 
 + E
62800 - 407.9 < 
 < 62800 - 407.9
62392.1 < 
 < 63207.9
(62392.1,63207.9)