Which one of the following statements is CORRECT for a significance level $\alpha = 0.05$ and $t_{0.025,60} = 2.0$?
Hint: Test statistic $t = \frac{R\sqrt{n - 2}}{\sqrt{1 - R^2}}$
The question asks to determine if the linear correlation between $X$ and $Y$ is statistically significant given a sample size, the Pearson correlation coefficient ($R$), a significance level ($\alpha$), and a critical value.
We perform a hypothesis test to check for significant linear correlation. The hypotheses are:
Given:
The test statistic formula is provided:
$ t = \frac{R\sqrt{n - 2}}{\sqrt{1 - R^2}} $
Substitute the given values:
$ t = \frac{0.27\sqrt{62 - 2}}{\sqrt{1 - (0.27)^2}} $
$ t = \frac{0.27\sqrt{60}}{\sqrt{1 - 0.0729}} $
$ t = \frac{0.27 \times 7.745966...}{\sqrt{0.9271}} $
$ t = \frac{2.091411...}{0.962860...} $
$ t \approx 2.172 $
We compare the absolute value of the calculated t-statistic with the critical t-value:
Since $|2.172| > 2.0$, the calculated test statistic falls in the rejection region.
We reject the null hypothesis ($H_0$). This indicates that there is sufficient statistical evidence to conclude that a linear correlation exists between $X$ and $Y$ at the $\alpha = 0.05$ significance level.
Therefore, $X$ and $Y$ are significantly linearly correlated.