T distribution can you help me

Consider a t distribution with 12 degrees of freedom. Compute P (-1.30 < t< 1.30) . Round your answer to at least three decimal places.

Consider a t distribution with 8 degrees of freedom. Find the value of c such that P(t > c) = 0.10 (the > has a line under it for this problem) . Round your answer to at least three decimal places

P ( -1.30 < t < 1.30) =?
C =?

If you have a TI graphing calculator, you can find an approximate answer as follows:
Hit 2ND, then DISTR. Go to "tcdf(" (the cumulative t-distribution function). Enter "-1.3 ,1.3 ,12" (the lower limit, the upper limit, then the degrees of freedom, each separated by commas). This gives the answer to part (a) as about .782.

For part (b), we see that P(t