In: Statistics and Probability
Background: Morris Saldov conducted a study in
Eastern and Central Newfoundland in 1988 to examine public
attitudes towards social spending. In particular, the study tried
to determine if knowing someone on public assistance (yes, no)
affected one's views on social spending (too little, about right,
too much). The data from the study is summarized in the table
below.
Yes | No | Total | |
Too little | 39 | 8 | 47 |
About right | 15 | 15 | 30 |
Too much | 9 | 9 | 18 |
Total | 63 | 32 | 95 |
Source: Morris Saldov, Public Attitudes to Social Spending in Newfoundland," Canadian Review of Social Policy, 26, November 1990, pages 10-14.
Directions: Conduct a chi-square test for independence to determine if the association between knowing someone on public assistance and views on social spending is statistically significant.
Yes | No | |
Too little | ||
About right | ||
Too much |
(a)
Correct option:
H0: There is no association between knowing someone on
public assistance and views on social spending.
Ha There is an association between knowing someone on public
assistance and views on social spending.
(b)
Expected counts Table is completed as follows:
Yes | No | |
Too little | ||
About right | ||
Too much |
(c)
The value of the test statistic. is got as follows:
Observed (O) | Expected (E) | (O - E)2/E |
39 | 31.17 | 1.97 |
8 | 15.83 | 3.87 |
15 | 19.89 | 1.20 |
15 | 10.11 | 2.37 |
9 | 11.94 | 0.72 |
9 | 6.06 | 1.42 |
Total = = | 11.56 |
So,
The value of the test statistic = = 11.56
(d)
ndf = (r - 1) X (c - 1)
= (3 - 1) X (2 - 1)
= 2
By Technology, p - value = 0.0031
Correct option:
The p-value provides strong evidence against the null hypothesis. The association between knowing someone on public assistance and attitudes towards social spending is statistically significant.