Laxmi wishes to test whether there is linear correlation between the mass and the height of adult males.
- State, with a reason, whether Laxmi should use a 1-tail or a 2-tail test. [1]
Laxmi chooses a random sample of 40 adult males and calculates Pearson's product-moment correlation coefficient, \(r\). She finds that \(r = 0.2705\).
- Use the table below to carry out the test at the 5% significance level. [5]
Critical values of Pearson's product-moment correlation coefficient.
| 1-tail test | 2-tail test |
| 5% | 2.5% | 1% | 0.5% |
| | | | |
| 10% | 5% | 2.5% | 1% |
| 38 | 0.2709 | 0.3202 | 0.3760 | 0.4128 |
| 39 | 0.2673 | 0.3160 | 0.3712 | 0.4076 |
| \(n\) 40 | 0.2638 | 0.3120 | 0.3665 | 0.4026 |
| 41 | 0.2605 | 0.3081 | 0.3621 | 0.3978 |