In: Statistics and Probability
The null and alternative hypotheses are:
H0:μd≤0
H1:μd>0
The following sample information shows the number of defective units produced on the day shift and the afternoon shift for a sample of four days last month.
| Day | ||||
| 1 | 2 | 3 | 4 | |
| Day shift | 11 | 11 | 16 | 19 | 
| Afternoon shift | 9 | 9 | 13 | 15 | 
At the 0.01 significance level, can we conclude there are more defects produced on the Afternoon shift?
a. State the decision rule. (Round the final answer to 3 decimal places.)
H0 is click to select (rejected, not rejected) if t> _____
b. Compute the value of the test statistic. (Round the final answer to 3 decimal places.)
Test statistic ______
c. What is your decision regarding the null hypothesis?
H0 should click to select (be rejected, not be rejected)
d. Determine the p-value. (Round the final answer to 4 decimal places.)
The p-value is _______
Answer:
Given that,
The null and alternative hypotheses are:


The following sample information shows the number of defective
units produced on the day shift and the afternoon shift for a
sample of four days last month.
| S.No | Day | |||
| 1 | 2 | 3 | 4 | |
| Day Shift | 11 | 11 | 16 | 19 | 
| Afternoon Shift | 9 | 9 | 13 | 15 | 
At the 0.01 significance level.
Can we conclude there are more defects produced on the Afternoon shift:
At the 0.01 significance level, and df=n-1=4-1=3, the critical value is 4.541.
Decision rule:
Reject H_0 if the tets statistic is t > 4.541.
Calculation table:
| S.No | Day(x1) | Afternoon(x2) | difference(d)=x1-x2 | d^2 | 
| 1 | 11 | 9 | 2 | 4 | 
| 2 | 11 | 9 | 2 | 4 | 
| 3 | 16 | 13 | 3 | 9 | 
| 4 | 19 | 15 | 4 | 16 | 
| Total |  d=11 | 
 d^2=33 | 
Then,
The mean(
):
=
d/n
=11/4
=2.75
The degrees of freedom (df)=n-1
=4-1
df=3
The standard deviation(s):





s=0.9575 (Approximately)
The standard error (SE):


=0.9575/2
SE=0.4788
The test statistic (t):

=(2.75-0)/0.4788
=2.75/0.4788
t=8.744(Approximately)
(a).
State the decision rule:
Decision rule:
Reject H_0 if the test statistic is t > 4.541.
(b).
Compute the value of the test statistic:
The value of the test statistic is t=8.744.
(c).
What is your decision regarding the null hypothesis:
Reject H_0.
(d).
Determine the p-value:
The p-value is 0.0016.
The result is significant at p < 0.01.