In: Statistics and Probability
A researcher is looking at the relationships between age and the number of instances of shoplifting. Use the data below to establish hypotheses and calculate the correlation for the relationship between age and shoplifting. State and explain your decision with regard to whether the H0 is ultimately rejected or accepted.
Age (X) |
Number of Times Shoplifted (Y) |
18 |
12 |
20 |
10 |
18 |
10 |
19 |
11 |
40 |
4 |
30 |
3 |
27 |
3 |
21 |
8 |
19 |
7 |
Solution:
Null and alternative hypothesis are
H0: = 0 vs H1 : 0
n = 9
X | Y | XY | X^2 | Y^2 | |
18 | 12 | 216 | 324 | 144 | |
20 | 10 | 200 | 400 | 100 | |
18 | 10 | 180 | 324 | 100 | |
19 | 11 | 209 | 361 | 121 | |
40 | 4 | 160 | 1600 | 16 | |
30 | 3 | 90 | 900 | 9 | |
27 | 3 | 81 | 729 | 9 | |
21 | 8 | 168 | 441 | 64 | |
19 | 7 | 133 | 361 | 49 | |
Sum | 212 | 68 | 1437 | 5440 | 612 |
Putting values
r = -0.787
Now ,
n = 9
df = n - 2 = 9 - 2 = 7
Take = 0.05
Using the critical value table for Pearson correlation coefficient, (two tailed )
Critical value are 0.666
r = -0.787
| r | = | -0.787| = 0.787
r > 0.666
reject H0
significance correlation.
YES , there is sufficient evidence to conclude that there is a linear correlation between the two variables.