Solution:
Here, we have to use chi square test for goodness of fit.
Null hypothesis: H0: The geographical distribution of the hotline callers is the same as the U.S. population.
Alternative hypothesis: Ha: The geographical distribution of the hotline callers is not same as the U.S. population.
We are given level of significance = α = 0.05
Test statistic formula is given as below:
Chi square = ∑[(O – E)^2/E]
Where, O is observed frequencies and E is expected frequencies.
We are given
N = 4
Degrees of freedom = df = N – 1 = 3
α = 0.05
Critical value = 7.814728
(by using Chi square table or excel)
Decision rule: Reject H0 if χ2 > 7.814728
Calculation tables for test statistic are given as below:
U.S. Population |
Hotline Caller (O) |
E |
Contribution to Chi square |
|
Northeast |
19 |
39 |
38 |
0.026315789 |
Midwest |
22.9 |
55 |
45.8 |
1.848034934 |
South |
35.6 |
60 |
71.2 |
1.761797753 |
West |
22.5 |
46 |
45 |
0.022222222 |
Total |
100 |
200 |
200 |
3.658370699 |
Chi square = ∑[(O – E)^2/E] = 3.658370699
P-value = 0.300795291
(By using Chi square table or excel)
P-value > α = 0.05
So, we do not reject the null hypothesis
There is sufficient evidence to conclude that the geographical distribution of the hotline callers is the same as the U.S. population.
Excel formulas for this test is given as below:
U.S. Population |
Hotline Caller (O) |
E |
Contribution to Chi square |
|
Northeast |
19 |
39 |
=38 |
=(H2-I2)^2/I2 |
Midwest |
22.9 |
55 |
45.8 |
=(H3-I3)^2/I3 |
South |
35.6 |
60 |
71.2 |
=(H4-I4)^2/I4 |
West |
22.5 |
46 |
45 |
=(H5-I5)^2/I5 |
Total |
=SUM(G2:G5) |
=SUM(H2:H5) |
=SUM(I2:I5) |
=SUM(J2:J5) |
P-value |
=CHIDIST(J6,3) |
|||
Critical Value |
=CHIINV(0.05,3) |
can someone help me finish this? on excel please. forgot the steps uestion 1. Problem 1 Contrib to X42 Hotline Callers (Oi) U.S. Population 19 22.9 35.8 22.5 Northeast Midwest South West 80 46 To...