In: Statistics and Probability
Are the types of positions held in the IT industry independent of how long individuals have worked in the industry? Researchers determine the position held and years in the industry for 246 individuals working in the IT industry. The data can be found in the excel file job. Run the appropriate tests and place the screen shot of your MiniTab or excel output below. Run all tests at the 5% significance level. When running a chi square test for association, you MUST check off “each cell’s contribution to Chi-Square” in MiniTab (this is found by selecting “statistics” when in the test dialog box). If using Excel you must complete these by hand within excel.When running a one-way or two-way ANOVA test, also perform a Fisher’s LSD comparison test for any significant factors, at the 5% significance level. Experience Manager Programmer Operator System Analyst 0-3 6 37 10 13 4-8 25 16 26 24 More than 8 47 10 12 20
Χ2 test of independence:
Ho: Positions held in the IT industry are independent of how long individuals have worked in the industry
Ha: Positions held in the IT industry are dependent on how long individuals have worked in the industry
Experience | Manager | Programmer | Operator | System Analyst | Total |
0 - 3 | 6 | 37 | 10 | 13 | 66 |
4 - 8 | 25 | 16 | 26 | 24 | 91 |
> 8 | 47 | 10 | 12 | 20 | 89 |
Total | 78 | 63 | 48 | 57 | 246 |
Note: To get expected value for a cell, the formula is (row total * column total)/grand total. For example, for the cell "0 - 3 and Manager", the expected value will be (66 * 78)/246 = 20.93. Similarly for all the other cells
Chi-square Contingency Table Test for Independence | |||||||
Manager | Programmer | Operator | System Analyst | Total | |||
0 - 3 | Observed | 6 | 37 | 10 | 13 | 66 | |
Expected | 20.93 | 16.90 | 12.88 | 15.29 | 66.00 | ||
O - E | -14.93 | 20.10 | -2.88 | -2.29 | 0.00 | ||
(O - E)² / E | 10.65 | 23.90 | 0.64 | 0.34 | 35.53 | ||
4 - 8 | Observed | 25 | 16 | 26 | 24 | 91 | |
Expected | 28.85 | 23.30 | 17.76 | 21.09 | 91.00 | ||
O - E | -3.85 | -7.30 | 8.24 | 2.91 | 0.00 | ||
(O - E)² / E | 0.51 | 2.29 | 3.83 | 0.40 | 7.03 | ||
> 8 | Observed | 47 | 10 | 12 | 20 | 89 | |
Expected | 28.22 | 22.79 | 17.37 | 20.62 | 89.00 | ||
O - E | 18.78 | -12.79 | -5.37 | -0.62 | 0.00 | ||
(O - E)² / E | 12.50 | 7.18 | 1.66 | 0.02 | 21.36 | ||
Total | Observed | 78 | 63 | 48 | 57 | 246 | |
Expected | 78.00 | 63.00 | 48.00 | 57.00 | 246.00 | ||
O - E | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | ||
(O - E)² / E | 23.66 | 33.37 | 6.13 | 0.77 | 63.92 | ||
63.92 | chi-square | ||||||
6 | df | ||||||
7.16E-12 | p-value |
Since the p- value < 0.05, we reject Ho
Conclusion: There is sufficient evidence that positions held in the IT industry are dependent on how long individuals have worked in the industry.