Answer:
Decision Rule: To reject the null hypothesis if t > 1.328
t = 3.913
Step-by-step explanation:
The summary of the given statistics include:
sample size n = 21
the correlation between the number of passengers and total fuel cost r = 0.668
(1) We are tasked to state the decision rule for 0.10 significance level
The degree of freedom df = n - 1
degree of freedom df = 21 - 1
degree of freedom df = 19
The null and the alternative hypothesis can be computed as:
[tex]H_o : \rho < 0\\ \\ Ha : \rho > 0[/tex]
The critical value for [tex]t_{\alpha, df}[/tex] is [tex]t_{010, 19}[/tex] = 1.328
Decision Rule: To reject the null hypothesis if t > 1.328
The test statistics can be computed as follows by using the formula for t-test for Pearson Correlation:
[tex]t = r*\sqrt{ \dfrac{(n-2)}{(1-r^2)}[/tex]
[tex]t = 0.668*\sqrt{ \dfrac{(21-2)}{(1-0.668^2)}[/tex]
[tex]t = 0.668*\sqrt{ \dfrac{(19)}{(1-0.446224)}[/tex]
[tex]t = 0.668*\sqrt{ \dfrac{(19)}{(0.553776)}[/tex]
[tex]t = 0.668*5.858[/tex]
t = 3.913144
t = 3.913 to 3 decimal places
