G two samples, one of size 14 and the second of size 13, are selected to test the difference between two population means. how m

Question

3 years ago

13

any degrees of freedom are used to find the critical value? assume the population standard deviations are equal.

1 answer:

vovikov84 [41] · Answer 1 · 2022-02-24T06:18:17+03:00

Note :- If sample size n > 30 OR Population standard deviation σ is given then We use Z test.

If sample size n < 30 AND Population standard deviation σ is unknown then we use t test.

In this question we are not given Population standard deviations σ1 and σ2.

Also n1 = 14 and n2 = 13 both sample sizes are LESS than 30.

Therefore we use t test.

Given :- Assume the population standard deviations are equal. ( σ1 = σ2)

then Degrees of freedom = n1 + n2 - 2 = 14 + 13 - 2 = 25.

(kindly find the image attached with this solution)

Answer :- Therefore 25 degrees of freedom are used to find the t critical value.