In: Statistics and Probability
Solution :
Given that,
Point estimate = sample mean =
= 176.30
Population standard deviation =
= 8.23
Sample size = n = 74
At 95% confidence level
= 1 - 95%
= 1 - 0.95 =0.05
/2
= 0.025
Z/2
= Z0.025 = 1.96
Margin of error = E = Z/2
* (
/n)
= 1.96 * ( 8.23 /
74)
= 1.88
At 95% confidence interval estimate of the population mean is,
± E
176.30 ± 1.88
( 174.42, 178.18 )
lower limit = 174.42
upper limit = 178.18