A) Find the t-value such that area in the right tail is 0.15 with 29 degrees of freedom

b) Find the t-value such that the area in the right tail is 0.25 with 5 degrees of freedom.

c) find the t-value such that the area left to the t-value is 0.02 with 13 degrees of freedom.

d) find the critical t-value that corresponds to 98% confidence. Assume 14 degrees of freedom.