In: Statistics and Probability
A sample of 34 observations is selected from a normal population. The sample mean is 30, and the population standard deviation is 3. Conduct the following test of hypothesis using the 0.05 significance level:
H0: μ = 31
H1: μ ≠ 31
a. Is this a one- or two-tailed test?
(Click to select) One-tailed test Two-tailed test
b. What is the decision rule?
Reject H0 and accept H1
when z does not lie in the region
from to .
c. What is the value of the test statistic? (Negative answer should be indicated by a minus sign. Round the final answer to 2 decimal places.)
Value of the test statistic
d. What is your decision regarding H0?
(Click to select) Fail to reject Reject H0
e. What is the p-value? (Round the final answer to 4 decimal places.)
The p-value is .
Solution :
= 31
=30
=3
n = 34
a )This is the two tailed test .
The null and alternative hypothesis is ,
H0 : = 31
Ha : 31
b ) Test statistic = z
= ( - ) / / n
= (30-31) / 3 / 34
= -1.94
c )Test statistic = z = -1.94
The significance level is \alpha = 0.05 α=0.05, and the critical value for a two-tailed test is Zc=1.96
it is observed that ∣z∣=-1.94 ≤ Zc =1.96, it is then concluded that the null hypothesis is not rejected
P-value = 2 * 0.0262 =0.0524
= 0.05
d )P-value >
0.0524 > 0.05
Fail to reject the null hypothesis .
There is insufficient evidence to suggest that