Answer:
Part a ) The degrees of freedom for the given two sample non-pooled t test is 24
Part b ) The degrees of freedom for the given two sample non-pooled t test is 30
Part c ) The degrees of freedom for the given two sample non-pooled t test is 30
Part d ) The degrees of freedom for the given two sample non-pooled t test is 25
Step-by-step explanation:
Degrees of freedom for a non-pooled two sample t-test is given by;
Δf = {[ s₁²/m + s₂²/n ]²} / {[( s₁²/m)²/m-1] + [(s₂²/n)²/n-1]}
Now given the information;
a) :- m = 12, n = 15, s₁ = 4.0, s₂ = 6.0
we substitute
Δf = {[ 4²/12 + 6²/15 ]²} / {[( 4²/12)²/12-1] + [(6²/15)²/15-1]}
Δf = 30184 / 1241
Δf = 24.3223 ≈ 24 (down to the nearest whole number)
b) :- m = 12, n = 21, s₁ = 4.0, s₂ = 6.0
we substitute using same formula
Δf = {[ s₁²/m + s₂²/n ]²} / {[( s₁²/m)²/m-1] + [(s₂²/n)²/n-1]}
Δf = {[ 4²/12 + 6²/21 ]²} / {[( 4²/12)²/12-1] + [(6²/21)²/21-1]}
Δf = 56320 / 1871
Δf = 30.1015 ≈ 30 (down to the nearest whole number)
c) :- m = 12, n = 21, s₁ = 3.0, s₂ = 6.0
we substitute using same formula
Δf = {[ s₁²/m + s₂²/n ]²} / {[( s₁²/m)²/m-1] + [(s₂²/n)²/n-1]}
Δf = {[ 3²/12 + 6²/21 ]²} / {[( 3²/12)²/12-1] + [(6²/21)²/21-1]}
Δf = 29095 / 949
Δf = 30.6585 ≈ 30 (down to the nearest whole number)
d) :- m = 10, n = 24, s₁ = 4.0, s₂ = 6.0
we substitute using same formula
Δf = {[ s₁²/m + s₂²/n ]²} / {[( s₁²/m)²/m-1] + [(s₂²/n)²/n-1]}
Δf = {[ 4²/10 + 6²/24 ]²} / {[( 4²/10)²/10-1] + [(6²/24)²/24-1]}
Δf = 1044 / 41
Δf = 25.4634 ≈ 25 (down to the nearest whole number).
