In: Statistics and Probability
We have a sample of 9254 participants, 4557 men and 4697 women. The mean age of the sample is 34.33 years; men mean age is 34.12 (Variance= 663.063). The Variance in the women's group is 637.5625. Can you calculate women mean age? If so, is there a statistically significant difference between men and women mean age?
total sum =9254*34.33 =317689.82
total of male =4557*34.12 =155484.84
so, mean of female = (317689.82 -155484.84)/4697
=34.53
.............
Ho : µ1 - µ2 = 0
Ha : µ1-µ2 ╪ 0
Level of Significance , α =
0.05
Sample #1 ----> sample 1
mean of sample 1, x̅1= 34.12
standard deviation of sample 1, s1 =
25.75
size of sample 1, n1= 4557
Sample #2 ----> sample 2
mean of sample 2, x̅2= 34.53
standard deviation of sample 2, s2 =
25.25
size of sample 2, n2= 4697
difference in sample means = x̅1-x̅2 =
34.1200 - 34.5 =
-0.41
pooled std dev , Sp= √([(n1 - 1)s1² + (n2 -
1)s2²]/(n1+n2-2)) = 25.4974
std error , SE = Sp*√(1/n1+1/n2) =
0.5302
t-statistic = ((x̅1-x̅2)-µd)/SE = ( -0.4100
- 0 ) / 0.53
= -0.773
Degree of freedom, DF= n1+n2-2 =
9252
p-value = 0.439339
(excel function: =T.DIST.2T(t stat,df) )
Conclusion: p-value>α , Do not reject null
hypothesis
There is not enough evidence to say taht there a
statistically significant difference between men and women
mean age
..................
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