Situation:
A survey was conducted to determine whether a proposed federal law should be passed to over haul the health care system in U.S. The following data was collected recording the number of people favoring the law based on their age group. It is believed that the distribution of the people favoring passing the law varies based on the age of the survey participants.
Action:
Using the chi-square goodness of fit test and either Excel or Minitab, determine whether age varies among survey participant favoring the proposed law. Use a .01 level of significance and the following observed frequencies of survey participants favoring passing the proposed law. Use the hypothesis testing procedure appropriate for this problem to help you make a decision.
Age of Survey Participants |
|
Frequency |
Under 20 |
|
23 |
20 to under 30 |
|
40 |
30 to under 40 |
|
56 |
40 to under 50 |
|
50 |
50 to under 60 |
|
32 |
Over 60 |
|
29 |
a)
Null and Alternate Hypothesis
H0: There is equal distribution for all the age years
H1: Law varies based on the age
Observed Values
Age of Survey Participants |
Under 20 |
20 to under 30 |
30 to under 40 |
40 to under 50 |
50 to under 60 |
Over 60 |
Total |
Frequency |
23 |
40 |
56 |
50 |
32 |
29 |
230 |
Degrees of Freedom = 6-1 = 5
Alpha = 0.01
Critical Value = 15.09
Expected Values
For Each Year = 230/6 = 38.3
Test Statistic:
Chi-Square = ∑(Oi-Ei)2/Ei
Chi-Square = (23-38.3)2/38.3 + ……. + (29-38.3)2/38.3 = 21.22
b)
p-value = 0.000736
c)
Results
Since the p-value is less than 0.01, we reject H0 with at least 99% confidence.
d)
Conclusion
At alpha = 0.01, we are confident that Law varies based on the age
Get Answers For Free
Most questions answered within 1 hours.