In: Statistics and Probability
Given the following information: the sample size n = 20, the sample mean= 75.3, and the population standard deviation= 6.0. Please show your work. Find the 0.99 confidence interval for
Solution :
Given that,
= 75.3
= 6.0
n = 20
At 99% confidence level the z is ,
= 1 - 99% = 1 - 0.99 = 0.01
/ 2 = 0.01 / 2 = 0.005
Z/2 = Z0.005 = 2.576
Margin of error = E = Z/2* ( /n)
= 2.576 * (6 / 20)
= 3.5
At 99% confidence interval estimate of the population mean is,
- E < < + E
75.3 - 3.5 < < 75.3 + 3.5
71.8 < < 78.8
(71.8 , 78.8 )