In: Statistics and Probability
A researcher wanted to learn whether the urge to smoke cigarettes was associated with the number of times a person exercised in the last week. So the researcher gathered 10 who smoke for the study. Participants were asked to rate their urge to smoke on a scale of 0 (no urge) to 10 (extreme urge), and to give the number of times each had worked out in the last week. Using the data below, an alpha of .05 (two-tailed), use a Pearson correlation to determine the outcome.
n the box below, provide the following information:
Null Hypothesis in sentence form (1 point):
Alternative Hypothesis in sentence form (1
point):
Critical Value(s) (2 points):
Calculations (4 points): Note: the more detail you provide, the more partial credit that I can give you if you make a mistake.
Outcome (determination of significance or not, and what this reflects in everyday language, 2 points)
Participant |
Smoking Urge |
Workouts |
1 |
6 |
2 |
2 |
7 |
1 |
3 |
3 |
3 |
4 |
3 |
5 |
5 |
5 |
1 |
6 |
3 |
2 |
7 |
5 |
4 |
8 |
6 |
0 |
9 |
4 |
2 |
10 |
3 |
3 |
x | y | (x - xbar) | (y - ybar) | (x - xbar)*(y - ybar) | (x - xbar)² | (y - ybar)² |
6 | 2 | 1.5 | -0.3 | -0.45 | 2.25 | 0.09 |
7 | 1 | 2.5 | -1.3 | -3.25 | 6.25 | 1.69 |
3 | 3 | -1.5 | 0.7 | -1.05 | 2.25 | 0.49 |
3 | 5 | -1.5 | 2.7 | -4.05 | 2.25 | 7.29 |
5 | 1 | 0.5 | -1.3 | -0.65 | 0.25 | 1.69 |
3 | 2 | -1.5 | -0.3 | 0.45 | 2.25 | 0.09 |
5 | 4 | 0.5 | 1.7 | 0.85 | 0.25 | 2.89 |
6 | 0 | 1.5 | -2.3 | -3.45 | 2.25 | 5.29 |
4 | 2 | -0.5 | -0.3 | 0.15 | 0.25 | 0.09 |
3 | 3 | -1.5 | 0.7 | -1.05 | 2.25 | 0.49 |
xbar | ybar | Σ(x - xbar) | Σ(y - ybar) | Σ(x - xbar)*(y - ybar) | Σ(x - xbar)² | Σ(y - ybar)² |
4.5 | 2.3 | 0 | 1.78E-15 | -12.5 | 20.5 | 20.1 |
r = Σ(x - xbar)*(y - ybar)/√Σ(x - xbar)²*Σ(y - ybar)² | -0.616 |
The hypothesis being tested is:
H0: ρ = 0
H0: The urge to smoke cigarettes was not associated with the number of times a person exercised in the last week.
Ha: ρ ≠ 0
Ha: The urge to smoke cigarettes was associated with the number of times a person exercised in the last week.
The critical value is 0.632.
Pearson's r is -0.616.
Since 0.61 < 0.632, we cannot reject the null hypothesis.
Therefore, we cannot conclude that the urge to smoke cigarettes was associated with the number of times a person exercised in the last week.