In: Statistics and Probability
Test the claim that the true population mean is statistically equal to 40, given a sample of 150 observations for which the mean is 41.6. Assume that the true population standard deviation is 9, and test at the .01 level of significance. Provide a complete solution using the classical approach
This is the two tailed test .
The null and alternative hypothesis is
H0 :
= 40
Ha :
40
Test statistic = z
= (
-
) /
/
n
= (41.6 - 40) / 9 /
150
= 2.177
Test statistic = 2.177
= 0.01
Critical value = 2.326
Fail to reject the null hypothesis .