In: Statistics and Probability
A survey of adults was conducted in which the subjects were asked whether they agree that the government should prohibit smoking in public places. In addition, each subject was asked how many people lived in their household. The results are summarized in the following contingency table. Use a 0.1 significance level to test for independence between the two variables.
3 or less |
More than 3 |
|
Agree |
82 |
70 |
Disagree |
67 |
75 |
A) Calculate the Table of Expected Values:
3 or less |
More than 3 |
|
Agree |
["69.22", "71.22", "77.03", "79.03"] |
["74.97", "70.25", "79.05", "77.41"] |
Disagree |
["72.96", "79.65", "70.55", "71.97"] |
["67.81", "70.03", "71.55", "76.21"] |
B) Calculate the Chi-Squared test statistic: ["1.346", "0.158", "2.826", "1.968", "1.789"]
C) Calculate the Critical Value: ["5.024", "7.879", "2.706", "3.841", "6.635"]
D) Based on this result, there ["does", "does not"] appear to be enough evidence to support the claim that the number of people in a household is independent of their view on smoking in public areas.
**NOTE the values in-between " " are possible answer choices
(A)
H0: Null Hypothesis: The variables: whether they agree that the government should prohibit smoking in public places and number of people lived in their household are independent (Claim)
HA: Alternative Hypothesis: The variables: whether they agree that the government should prohibit smoking in public places and number of people lived in their household are dependent
Observed Frequencies:
3 or less | More than 3 | Total | |
Agree | 82 | 70 | 152 |
Disagree | 67 | 75 | 142 |
Total | 149 | 145 | 294 |
Expected Frequencies:
3 or less | More than 3 | Total | |
Agree | 149 X 152/ 294 = 77.034 | 145 X 152/ 294 = 74.966 | 152 |
Disagree | 149 X 142/ 294 = 71.966 | 145 X 142/ 294 = 70.034 | 142 |
Total | 149 | 145 | 294 |
So, Answer is:
3 or less | More than 3 | |
Agree | 77.03 | 74.97 |
Disagree | 71.97 | 70.03 |
(B)
The Chi-Squared test statistic is got as follows:
Observed (O) | Expected (E) | (O - E)2/E |
149 | 77.034 | 0.320 |
70 | 74.966 | 0.329 |
67 | 71.966 | 0.343 |
75 | 70.034 | 0.352 |
Total = | 1.346 |
So,
Correct option:
1.346
(C)
= 0.10
df = (2 - 1) X (2 - 1) = 1
From Table, critical value of = 2.706
So,
Correct option:
2.706
(D)
Correct option:
Based on this result, there does appear to be enough evidence to support the claim that the number of people in a household is independent of their view on smoking in public areas.