In: Statistics and Probability
1. What trends do you notice in your data set?
2.Based on the trends and the history of your data set, make a claim. What kind of test (left, right, two tailed) would you have to complete?
3.Explain the steps needed to complete the Hypothesis Test. What is needed?
Location | Data Type | 2007 | 2008 | 2009 | 2010 | 2011 | 2012 | 2013 | 2014 | 2015 | 2016 |
---|---|---|---|---|---|---|---|---|---|---|---|
New York |
Number |
31,187 |
30,061 |
30,229 |
28,124 |
26,302 |
25,759 |
25,378 |
25,398 |
24,656 |
24,073 |
Percent |
12% |
12% |
12% |
12% |
11% |
11% |
11% |
11% |
10% |
10% |
Solution:
Question 1
We notice that the data is uniformly distributed through the year 2007 to 2016.
Question 2
Based on the trends and history of given data, the claim is that the given data is uniformly distributed through the year 2007 to 2016.
Here, we have to use Chi square test for goodness of fit and this test is two tailed.
Question 3
Here, we have to use chi square test for goodness of fit.
Null hypothesis: H0: The given data is uniformly distributed through the year 2007 to 2016.
Alternative hypothesis: Ha: The given data is not uniformly distributed through the year 2007 to 2016.
We assume 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 = 10
Degrees of freedom = df = N – 1 = 10 – 1 = 9
α = 0.05
Critical value = 16.91897762
(by using Chi square table or excel)
Calculation tables for test statistic are given as below:
Year |
O |
E |
(O - E)^2 |
(O - E)^2/E |
2007 |
31187 |
27116.7 |
16567342 |
610.9645381 |
2008 |
30061 |
27116.7 |
8668902.5 |
319.688697 |
2009 |
30229 |
27116.7 |
9686411.3 |
357.212024 |
2010 |
28124 |
27116.7 |
1014653.3 |
37.41802247 |
2011 |
26302 |
27116.7 |
663736.09 |
24.47702302 |
2012 |
25759 |
27116.7 |
1843349.3 |
67.97837827 |
2013 |
25378 |
27116.7 |
3023077.7 |
111.4839818 |
2014 |
25398 |
27116.7 |
2953929.7 |
108.9339665 |
2015 |
24656 |
27116.7 |
6055044.5 |
223.2957731 |
2016 |
24073 |
27116.7 |
9264109.7 |
341.638536 |
Total |
271167 |
271167 |
2203.09094 |
Chi square = ∑[(O – E)^2/E] = 2203.09094
P-value = 0.00
(By using Chi square table or excel)
P-value < α = 0.05
So, we reject the null hypothesis
There is insufficient evidence to conclude that the given data is uniformly distributed through the year 2007 to 2016.