rmine the t-value in each of the cases. nd the t-value such that the area in the right tail is 0.15 with 30 degrees of freed Round to three decimal places as needed.) nd the t-value such that the area in the right tail is 0.20 with 30 degrees of freed Round to three decimal places as needed.) nd the t-value such that the area left of the t-value is 0.01 with 15 degrees of fre symmetry.] Round to three decimal places as needed.) nd the critical t-value that corresponds to 80% confiden