In: Statistics and Probability
Based on a simple random sample of 35 adult males in North America, it is found that the sample average height is 171cm with a sample standard deviation of 6cm. Construct 95% confidence interval for the mean height of all adult males in North America.
PLEASE SHOW THE WORK
solution
Given that,
= 171
s =6
n = 35
Degrees of freedom = df = n - 1 = 35- 1 =34
At 95% confidence level the t is ,
= 1 - 95% = 1 - 0.95 = 0.05
/ 2 = 0.05 / 2 = 0.025
t /2,df = t0.025,34 = 2.032 ( using student t table)
Margin of error = E = t/2,df * (s /n)
=2.032 * (6 / 35) = 2.0608
The 95% confidence interval estimate of the population mean is,
- E < < + E
171 - 2.0608 < < 171+ 2.0608
168.9392 < < 173.0608
(168.9392 ,173.0608 )