Determine the​ upper-tail critical value tα/2 in each of the following circumstances.

a. 1−α=0.99, n=10

b. 1−α=0.95, n=10

c. 1−α=0.99, n=63

d. 1−α=0.99, n=53

e. 1−α=0.90, n=17

t=?

​(Round to four decimal places as​ needed.)