In: Statistics and Probability
The table below lists the earnings (in thousands of dollars) of a random sample of 12 male and 12 female salespersons. At alpha = 0.10 can you conclude that there is a difference between males’ and females’ earnings?
Male |
28 |
43 |
64 |
51 |
48 |
44 |
36 |
45 |
67 |
49 |
40 |
65 |
Female |
36 |
27 |
51 |
43 |
35 |
48 |
41 |
37 |
34 |
47 |
50 |
43 |
The claim is “there is a difference between males’ and females’ earnings”
1) null and alternate hypothesis
H0:
H1:
2) level of significance = 0.10
3) test statistics
For malw
N1: 5
df1 = N - 1 = 6 - 1 = 5
M1: 46.33
SS1: 689.33
s21 = SS1/(N - 1) = 689.33/(6-1) =
137.87
For female
N2: 6
df2 = N - 1 = 6 - 1 = 5
M2: 40
SS2: 404
s22 = SS2/(N - 1) = 404/(6-1) =
80.8
T-value Calculation
s2p = ((df1/(df1 +
df2)) * s21) + ((df2/(df2 +
df2)) * s22) = ((5/10) * 137.87) + ((5/10) *
80.8) = 109.33
s2M1 = s2p/N1 =
109.33/6 = 18.22
s2M2 = s2p/N2 =
109.33/6 = 18.22
t = (M1 - M2)/√(s2M1 +
s2M2) = 6.33/√36.44 = 1.05
4) p value = 0.3188
5) since p value is greater than level of significance so we fail to reject H0
6) so there insufficient evidence to conclude that there is a difference between males and females earning.