In: Statistics and Probability
Scores in the first and fourth (final) rounds for a sample of 20 golfers who competed in golf tournaments are shown in the following table.
Player | First Round |
Final Round |
---|---|---|
Golfer 1 | 70 | 72 |
Golfer 2 | 71 | 72 |
Golfer 3 | 70 | 74 |
Golfer 4 | 72 | 71 |
Golfer 5 | 70 | 69 |
Golfer 6 | 67 | 67 |
Golfer 7 | 71 | 67 |
Golfer 8 | 68 | 75 |
Golfer 9 | 67 | 72 |
Golfer 10 | 70 | 69 |
Player | First Round |
Final Round |
---|---|---|
Golfer 11 | 72 | 72 |
Golfer 12 | 72 | 70 |
Golfer 13 | 70 | 73 |
Golfer 14 | 70 | 76 |
Golfer 15 | 68 | 70 |
Golfer 16 | 68 | 66 |
Golfer 17 | 71 | 70 |
Golfer 18 | 70 | 68 |
Golfer 19 | 69 | 68 |
Golfer 20 | 67 | 71 |
Suppose you would like to determine if the mean score for the first round of a golf tournament event is significantly different than the mean score for the fourth and final round. Does the pressure of playing in the final round cause scores to go up? Or does the increased player concentration cause scores to come down?
a) Calculate the value of the test statistic. (Round your answer to
three decimal places.)
Calculate the p-value. (Round your answer to four decimal places.)
b) What is the point estimate of the difference between the two population means? (Use mean score first round − mean score fourth round.)
Answer:
Given that,
Scores in the first and fourth (final) rounds for a sample of 20 golfers who competed in golf tournaments are shown in the following table.
Player | First Round |
Final Round |
---|---|---|
Golfer 1 | 70 | 72 |
Golfer 2 | 71 | 72 |
Golfer 3 | 70 | 74 |
Golfer 4 | 72 | 71 |
Golfer 5 | 70 | 69 |
Golfer 6 | 67 | 67 |
Golfer 7 | 71 | 67 |
Golfer 8 | 68 | 75 |
Golfer 9 | 67 | 72 |
Golfer 10 | 70 | 69 |
Player | First Round |
Final Round |
---|---|---|
Golfer 11 | 72 | 72 |
Golfer 12 | 72 | 70 |
Golfer 13 | 70 | 73 |
Golfer 14 | 70 | 76 |
Golfer 15 | 68 | 70 |
Golfer 16 | 68 | 66 |
Golfer 17 | 71 | 70 |
Golfer 18 | 70 | 68 |
Golfer 19 | 69 | 68 |
Golfer 20 | 67 | 71 |
To test the hypothesis is that the mean score for the first round of a golf tournament event is significantly different than the mean score for the fourth and final round 10% level of significance.
The null and alternative hypothesis is:
(a).
The t-test statistics is,
By using MegaStat, find t-test statistics with the help of following steps is:
1). Import the data.
2). Select the MegaStat from Add-Ins option.
3). Select the Paired Observations groups from Hypothesis Tests.
4). Select data input.
5). Select confidence level. Test difference and alternative hypothesis.
6). Select t-test.
7). Click Ok.
Hypothesis Test: Paired Observations 0.000-hypothesized value 69.650-Mean first 70.550-Mean final -0.900- Mean difference (First-Final) 2.954- std. dev 0.661- std.error 20- n 19- df -1.363- t .1890- p-value (two tailed) -2.042- Confidence interval 90% lower 0.242 - Confidence interval 90% upper 1.142 -Margin of error |
From the MegaStat output, the t-test statistics is -1.363.
The p-value for this test is,
From the MegaStat output, the p-value for this test is 0.1890.
Decision :
The conclusion is that the p-value in this context is higher than 0.10 which is 0.1890, so the null hypothesis is not rejected at 1% level of significance. There is insufficient evidence to indicate that the mean score for the first round of a golf tournament even is significantly different than the mean score for the fourth and final round. The result is not statistically significant.
(b).
The point estimate of the difference between the two population means is,
For a MegaStat output in part (a), the point estimate of the difference between the two population means is -0.90.