6. A student, considering options for the future, collects data on education and salary. The table below shows the highest level of education attained and the salary bracket of a random sample of 664 people.
| Fewer than 5 GCSE | 5 or more GCSE | 3 A Levels | University degree | Post graduate qualification | Total |
| Less than £20000 | 18 | 32 | 20 | 28 | 10 | 108 |
| £20000 to £60000 | 50 | 95 | 112 | 155 | 50 | 462 |
| More than £60000 | 3 | 22 | 29 | 35 | 5 | 94 |
| Total | 71 | 149 | 161 | 218 | 65 | 664 |
By conducting a chi-squared test for independence, the student investigates the relationship between the highest level of education attained and the salary earned.
- State the null and alternative hypotheses.
- The table below shows the expected values. Calculate the value of \(k\).
| Expected values | Fewer than 5 GCSE | 5 or more GCSE | 3 A Levels | University degree | Post graduate qualification |
| Less than £20000 | \(k\) | 24.23 | 26•19 | 35.46 | 10.57 |
| £20000 to £60000 | 49.40 | 103.67 | 112.02 | 151.68 | \(45 \cdot 23\) |
| More than £60000 | 10.05 | 21.09 | \(22 \cdot 79\) | 30.86 | 9.20 |
- The following computer output is obtained. Calculate the values of \(m\) and \(n\).
| Chi Squared Contributions | Fewer than 5 GCSE | 5 or more GCSE | 3 A Levels | University degree | Post graduate qualification |
| Less than £20000 | 3.604530799 | \(m\) | 1.46165 | 1.5686 | 0.03098 |
| £20000 to £60000 | 0.007272735 | 0.72535 | 4E-06 | 0.07264 | 0.50396 |
| More than £60000 | \(4 \cdot 946619863\) | 0.03897 | 169081 | \(0 \cdot 55498\) | \(n\) |
X-squared \(= 19 \cdot 61301 , d f = 8 , p\)-value \(= 0 \cdot 0119\) - Without carrying out any further calculations, explain how X-squared \(= 19 \cdot 61301\) (the \(\chi ^ { 2 }\) test statistic) was calculated.
- Comment on the values in the "Fewer than 5 GCSE" column of the table in part (c).
- The student says that the highest levels of education lead to the highest paying jobs. Comment on the accuracy of the student's statement.