Question

# of OpenLab visits	Final grade
2	40
8	85
10	80
9	84
15	90
7	72
5	50
4	59
8	85
10	70
7	66
7	70
5	63
4	60
4	59
11	79
3	82
9	90
10	82
9	76
14	85
6	73
5	41
4	56
8	80
10	70
7	66
9	88
5	65
4	70
4	62
11	90

Open Lab Visits data. Using data on 33 second-year students enrolled in a Statistics course, test if more visits to open lab sessions lead to higher final grades.

9. What test/procedure did you perform? (5 points)

• a. One-sided t-test
• b. Two sided t-test
• c. Regression
• d. Confidence Interval

10. What is the P-value/margin of error? (5 points)

• a. 2.14E-24
• b. 2.56E-06
• c. 4.29E-24
• d. 2.85E-12

11. What is the Statistical interpretation? (5 points)

• a. The P-value is much smaller than 5% thus we are very certain that the averages are different.
• b. The P-value is much greater than 5% thus we are very certain that the slope is not zero.
• c. The P-value is much smaller than 5% thus we can claim that number of visits to open lab sessions is related to final grade.
• d. None of these

12. What is the conclusion? (5 points)

• a. The test is inconclusive and more data is needed.
• b. We are confident that more visits to open lab sessions lead to higher final grades.
• c. We cannot be confident that more visits to open lab sessions lead to higher final grades.
• d. None of these.

Answer 1

9)

One sided t test will be used

10)

We have to find p value and margin of error

Let us find the pooled square variance

Sp^2=(n1-1)*S1^2+(n2-1)*S2^2/(n1-1)+(n2-1)

=(32-1)*13.67^2+(32-1)*3.16^2/(32-1)+(32-1)

=98.37

=71.5-7.3125/2.48

=25.89

The P-Value is < .00001

c)

option A is correct

The P-value is much smaller than 5% thus we are very certain that the averages are different

d)

Option B is correct

We are confident that more visits to open lab sessions lead to higher final grades.