Question

1) You are performing a two-tailed test with a sample size of 61.
If α=.002α=.002, find the positive critical value, to three decimal places.
tα/2=

2) You are performing a left-tailed test with a sample size of 22.
If α=.001α=.001, find the critical value, to three decimal places.
tα=

3) You are performing a right-tailed test with a sample size of 99.
If α=.05α=.05, find the critical value, to three decimal places.
tα=

Answer 1

solution

n =61

Degrees of freedom = df = n - 1 =61 - 1 = 60

= 0.002

/ 2 = 0.002/ 2 = 0.001

t _/2,df = t_0.001,60 =3.232 ( using student t table)

(b)

n =22

Degrees of freedom = df = n - 1 =22 - 1 = 21

= 0.001

t_,df = t_0.001,21 =3.527 ( using student t table)

(c)

n =99

Degrees of freedom = df = n - 1 =99 - 1 = 98

= 0.05

t_,df = t_0.05,98 =1.661 ( using student t table)