Question

At a local university, a sample of 49 evening students was selected in order to determine whether the average age of the evening students is significantly different from 21. The average age of the students in the sample was 23 years. The population standard deviation is known to be 3.5 years. Use a 0.05 level of significance (z 0.05= -1.64 and z0.95 = 1.64). Show all four steps of the hypothesis testing. show work by steps

Answer 1

This hypothesis test is a two tailed test .

The null and alternative hypothesis is

H₀ : = 21

H_a : 21

Test statistic = z

= ( - ) /    / n

= (23 - 21) / 3.5 / 49

= 4

Test statistic = 4

Critical value = +/-1.96

Reject the null hypothesis .

There is sufficient evidence to conclude that the evening students is significantly different from 21.