In: Statistics and Probability
**Data retrieved from Center for Disease Control (April 22, 2020)**
Observed Frequencies |
|
Wyoming |
430 |
N. Dakota |
627 |
Nebraska |
1648 |
S. Dakota |
1675 |
Null hypothesis : The 4 states have equal proportion of cases
Alternate hypothesis: At least one state have different proportion
alpha = 0.05
Event | Observed Frequency(O) | Expected Probability | Expected Frequency ( E) | ( O-E)^2 | ( O-E)^2/E |
Wyoming | 430 | 0.25 | 1095 | 442225 | 403.8584475 |
N. Dakota | 627 | 0.25 | 1095 | 219024 | 200.0219178 |
Nebraska | 1648 | 0.25 | 1095 | 305809 | 279.2776256 |
S. Dakota | 1675 | 0.25 | 1095 | 336400 | 307.2146119 |
Total | 4380 | 1 | 4380 | 1303458 | 1190.372603 |
The chi square statistic = 1190.372
The corresponding p value is 0.00000
Since p < alpha ( 0.05 )
We reject the null hypothesis
or, At least one state have different proportion