Final answer:
The upper-tail critical values tα/2 for each given circumstance are as follows: a. 2.660; d. 2.831; b. 1.659; e. 2.011; c. 3.355.
Step-by-step explanation:
To find the upper-tail critical value tα/2 in each situation, we need to refer to the table of critical values for the t distribution. Since we don't have access to the table here, let me provide the values:
a. For 1-α = 0.99 and n = 59, the upper-tail critical value tα/2 is 2.660.
d. For 1-α = 0.99 and n = 21, the upper-tail critical value tα/2 is 2.831.
b. For 1-α = 0.90 and n = 59, the upper-tail critical value tα/2 is 1.659.
e. For 1-α = 0.95 and n = 52, the upper-tail critical value tα/2 is 2.011.
c. For 1-α = 0.99 and n = 8, the upper-tail critical value tα/2 is 3.355.