Question

Find the critical value of t from Appendix D for the following situations. Specify the correct degrees of freedom, whether the value is “+/-“ or is “+ or –“ and, if the actual df value isn’t the table, specify which you used.

a) N = 31, α = .05, one-tailed one sample t-test    _______________________________

b) N = 25, α = .01, two-tailed one sample t-test   _______________________________

c) N = 26, α = .05, one-tailed one sample t-test    _______________________________

d) N = 41, α = .01, one-tailed one sample t-test    ___________

e) N = 30, α= .05, two-tailed one sample t-test     _______________________________

f) N = 121, α=.01, two-tailed one sample t-test.

Answer 1

A) df = 31 - 1 = 30

At = 0.05, for left-tailed t-test the critical value is t^* = -1.697

At = 0.05, for right-tailed t-test the critical value is t^* = 1.697

b) df = 25 - 1 = 24

At = 0.01, for two - tailed t-test the critical values are t^* =  +/- 2.797

C) df = 26 - 1 = 25

At = 0.05, for left-tailed t-test the critical value is t^* = -1.706

At = 0.05, for right-tailed tailed t-test, the critical value is t^* = 1.706

D) df = 41 - 1 = 40

At = 0.01, for left-tailed t-test the critical value is t^* = -2.423

At = 0.01, for right-tailed t-test the critical value is t^* = 2.423

E) df = 30 - 1 = 29

At = 0.05, for two-tailedtwo-tailed t-test the critical value is t^* = +/- 2.045

F) df = 121 - 1 = 120

At = 0.01, for two-tailed t-test the critical values are t^* = +/- 2.617