Question

1. Identify the correct critical value for tin a two sample (independent), two-tailed test with 30 degrees of freedom at a .05level of significance.

2. Identify the correct critical value for tin a two sample (independent), one-tailed test with 40 degrees of freedom at a .01level of significance.

3. The level of significance (a) represents the probability of making a(n) _____________.

4.A Type I error can be described as  

.

Answer 1

Solution:

1)

two sample (independent),

two-tailed test

df = 30

= 0.05

/2 = 0.025

For two tailed test there are two critical values.

= t_0.025,30 = 2.042

Required critical values are -2.042 , 2.042

2)

For one tailed test ,

critical value is   = t_0.01,40 = 2.423

3)

The level of significance (a) represents the probability of making a Type I error.

4)

A Type I error can be described as

"Rejecting the null hypothesis , when , in fact he null hypothesis is true. "