State the total degrees of freedom for the following

Question

State the total degrees of freedom for the following t-tests. (If you need to use ∞, enter INFINITY.)

(a) n = 17 for a one-independent sample t-test

(b) df₁ = 12, n₂ = 18 for a two-independent sample t-test

(c) critical value = 1.645 for a one-tailed test, α = 0.05

(d) critical value = 63.657 for a two-tailed test, α = 0.01