HW What is the null hypothesis?
| AFC | |
| AFC Team Name | Number of times sacked |
| Ravens | 57 |
| Bangles | 55 |
| Steelers | 38 |
| Browns | 49 |
| Bills | 27 |
| Dolphins | 40 |
| Patriots | 28 |
| Jets | 53 |
| Texans | 44 |
| Colts | 32 |
| Jaguars | 32 |
| Titans | 47 |
| Broncos | 40 |
| Kansas City | 28 |
| Raiders | 40 |
| Chargers | 31 |
|
NFC |
|
| NFC Team Name | Number of times sacked |
| Bears | 58 |
| Lions | 36 |
| Packers | 33 |
| Vikings | 30 |
| Cowboys | 33 |
| Giants | 38 |
| Eagles | 31 |
| Washington | 43 |
| Falcons | 40 |
| Panthers | 52 |
| Saints | 37 |
| Buccaneers | 23 |
| Cardinals | 39 |
| Rams | 31 |
| 49ers | 33 |
| Seahawks | 46 |
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Bottom of Form
QUESTIONS:
1: What is the null hypothesis?
2: What is the alternative hypothesis?
3: What is the risk level?
Group of answer choices
.01
.05
.5
.25
4: What is the best statistical test to use?
Group of answer choices
ANOVA
t-Test for independent samples
correlation test
z-test
t-Test for dependent samples
5: Compute the test statistic. The formula is below for you. Also, remember to use the variance rather than the standard deviation in your calculation. You have already calculated the variance for your previous assignment, so that part is already done! Put your calculated t value below, round your answer to two decimal places:
6: Now it’s time to compare our obtained value (the one you just calculated) to the critical value. First, we’ll need the degrees of freedom. What are the degrees of freedom?
Group of answer choices
28
40
19
30
7: Should we use a “one tailed” or a “two tailed” test for this?
Hint: To figure this out, think about whether it is directional or non-directional. Take a look at your alternative hypothesis (above!), and think about the prompt for the assignment—did we expect there to be more sacks in one group than the other or were simply testing whether they were different?
Group of answer choices
one tailed
two tailed
8: What is the critical value for this statistical test? (hint: you’ll need your answers to the previous two questions, as well as your “level of risk”; remember, if the exact degrees of freedom aren’t in the t-test table of critical values, you can choose the closest value that is there).
Group of answer choices
2.049
1.701
2.043
1.562
9: Write up your results as you would see it in a results section of an empirical research paper (in APA style). Make sure to include the means and SDs.
10: Based on your answer to the previous question, what is your decision?
Group of answer choices
Reject the null hypothesis
Fail to reject the null hypothesis
Not enough information to decide
11: Imagine that you also wanted to compare if there was a difference in the number of touch towns scored between the NFC and AFC. You write up the following results:
An independent samples t-Test comparing the average number of touchdowns scored during the regular season between the NFC and AFC was statistically significant, t(30) = 1.92, p < .05. The number of touchdowns scored by the teams in the AFC (M = 25.125, SD = 7.54) than the NFC (M = 22.25, SD = 2.54.
Calculate the effect size for this new t-test, using the Pooled Variance Formula (Below). Round your answer to two decimal places.
12: What “size” is this effect size?
Group of answer choices
Small
Medium
There isn’t enough information to answer this question.
Large
