Question

Consider the following hypothesis test for the mean of a normally distributed population: Ho: μ=80. A random sample of size 40 is to be taken. The population standard deviation is 20. Write the rejection rule using critical value method; use α=4%. Please clearly identify the test-statistic (t or z or F etc).

Answer 1

Solution :

This is the two tailed test,  

The null and alternative hypothesis is ,

H0 :   = 80

Ha : 80

standard deviation = = 20

n = 40

= 0.04

/2 = 0.02

Z/2 = Z0.02 = 2.05

rejection region = z < -2.05 or z > 2.05