If a sample of size 18 has a linear correlation coefficient
If a sample of size 18 has a linear correlation coefficient of -0.64 is there significant reason to conclude that the linear correlation coefficient of the population is negative? Use = 0.01.
Which of the following is correct?
Reject the null hypothesis, there is not significant evidence of a negative linear correlation
Reject the null hypothesis, there is significant evidence of a negative linear correlation.
Fail to reject the null hypothesis, there is not significant evidence of a negative linear correlation.
Fail to reject the null hypothesis, there is significant evidence of a negative linear correlation.
Solution
As
t = r sqrt[(n - 2)/(1 - r^2)]
Solving for t,
t = -3.3317
As df = n - 2 = 16, then the p value for this two tailed test is
p = 0.004227274 < 0.01.
Thus, we REJECT THE NULL HYPOTHESIS, THERE IS A SIGNIFICANT EVIDENCE OF NEGATIVE LINEAR CORRELATION. [ANSWER, OPTION 2]
