In: Statistics and Probability
Determine the number of degrees of freedom for the two-sample t test or CI in each of the following situations. (Round your answers down to the nearest whole number.)
(a) m = 12, n = 10,
s1 = 5.0, s2 = 6.0
(b) m = 12, n = 18,
s1 = 5.0, s2 = 6.0
(c) m = 12, n = 18,
s1 = 3.0, s2 = 6.0
(d) m = 10, n = 24,
s1 = 5.0, s2 = 6.0
SOLUTION:
From given data,
Determine the number of degrees of freedom for the two-sample t test or CI in each of the following situations.
(a) m = 12, n = 10, s1 = 5.0, s2 = 6.0
df = [ / + / ]2 / [( / )2 / ( -1 ) + ( / )2 / ( -1 ) ]
df = [ 5.02 / 12 + 6.02 / 10 ]2 / [( 5.02 / 12 )2 / (12 -1 ) + (6.02 / 10 )2 / (10 -1 ) ]
df =32.300278 / [0.394570 +1.44]
df =32.300278 /1.83457
df =17.606
df =18 (Round your answers down to the nearest whole number.)
(b) m = 12, n = 18, s1 = 5.0, s2 = 6.0
df = [ / + / ]2 / [( / )2 / ( -1 ) + ( / )2 / ( -1 ) ]
df = [ 5.02 / 12 + 6.02 / 18 ]2 / [( 5.02 / 12 )2 / (12 -1 ) + (6.02 / 18 )2 / (18 -1 ) ]
df =16.67361 /[ 0.3945707 +0.235294]
df =16.67361 /0.6298647
df =26.4717327
df =27 (Round your answers down to the nearest whole number.)
(c) m = 12, n = 18, s1 = 3.0, s2 = 6.0
df = [ / + / ]2 / [( / )2 / ( -1 ) + ( / )2 / ( -1 ) ]
df = [ 3.02 / 12 + 6.02 / 18 ]2 / [( 3.02 / 12 )2 / (12 -1 ) + (6.02 / 18 )2 / (18 -1 ) ]
df =7.5625 /[ 0.051136 +0.2352941]
df =7.5625 /0.2864301
df =26.4026022
df =27 (Round your answers down to the nearest whole number.)
(d) m = 10, n = 24, s1 = 5.0, s2 = 6.0
df = [ / + / ]2 / [( / )2 / ( -1 ) + ( / )2 / ( -1 ) ]
df = [ 5.02 / 10 + 6.02 / 24 ]2 / [( 5.02 / 10 )2 / (10 -1 ) + (6.02 / 24 )2 / (24 -1 ) ]
df =16 /[ 0.6944 +0.09782608]
df =16 /0.79222608
df =20.196255
df =20 (Round your answers down to the nearest whole number.)