In: Statistics and Probability
A random sample of firms that relocated to Texas in the last three years is conducted. Based on the contingency table to the right, provide a test of whether the industry type and primary reason for relocation are statistically independent at a significance level of α=0.05. |
Industry | ||||
Primary Reason | Manufacturing | Retail | Tourism | Row Total |
Technology | 53 | 25 | 10 | 88 |
Tax Credits | 67 | 36 | 20 | 123 |
Labor Force | 30 | 40 | 33 | 103 |
Column Total | 150 | 101 | 63 |
314 |
a. Calculated Chi-Squared statistic |
b. Critical (upper) Chi-Square for α=5% |
c. Conclusion for α=5% |
Null hypothesis : Ho : Industry type and primary reason for relocation are statistically independent
Alternate Hypothesis : Ha : Industry type and primary reason for relocation are not statistically independent
a.
Test Statistic
O : Observed Frequency
E: Expected Frequency
Given,
O: Observed Frequency | Industry | |||
Primary Reason | Manufacturing | Retail | Tourism | Row Total |
Technology | 53 | 25 | 10 | 88 |
Tax Credits | 67 | 36 | 20 | 123 |
Labor Force | 30 | 40 | 33 | 103 |
Column Total | 150 | 101 | 63 | 314 |
E: Expected Count/Frequency | Manufacturing | Retail | Tourism |
Technology | (88*150) / 314 | (88*101) / 314 | (88*63) / 314 |
Tax Credits | (123*150) / 314 | (123*101) / 314 | (123*63) / 314 |
Labor Force | (103*150) / 314 | (103*101) / 314 | (103*63) / 314 |
E: Expected Count/Frequency | Manufacturing | Retail | Tourism | Row total |
Technology | 42.0382 | 28.3057 | 17.6561 | 88 |
Tax Credits | 58.7580 | 39.5637 | 24.6783 | 123 |
Labor Force | 49.2038 | 33.1306 | 20.6656 | 103 |
Column Total | 150 | 101 | 63 | 314 |
O | E | O-E | (O-E)2 | (O-E)2/E |
53 | 42.0382 | 10.9618 | 120.1607 | 2.8584 |
25 | 28.3057 | -3.3057 | 10.9279 | 0.3861 |
10 | 17.6561 | -7.6561 | 58.6151 | 3.3198 |
67 | 58.7580 | 8.2420 | 67.9312 | 1.1561 |
36 | 39.5637 | -3.5637 | 12.6999 | 0.3210 |
20 | 24.6783 | -4.6783 | 21.8869 | 0.8869 |
30 | 49.2038 | -19.2038 | 368.7868 | 7.4951 |
40 | 33.1306 | 6.8694 | 47.1890 | 1.4243 |
33 | 20.6656 | 12.3344 | 152.1373 | 7.3619 |
Total | 25.2095 |
Test Statistic
b.
Degrees of freedom = (number of rows-1)*(number of columns -1) =(3-1)*(3-1) =4
Critical value of for =5%(0.05) for 4 degrees of freedom = 9.49
c.
As Value of the test statistic : 25.2095 > Critical value of :9.49; Reject the null hypothesis.
There is sufficient evidence to conclude that Industry type and primary reason for relocation are not statistically independent