4 The back-to-back stem-and-leaf diagram shows the annual salaries of 19 employees at each of two companies, Petral and Ravon.
| Petral | | Ravon |
| \multirow{7}{*}{99} | | 3 | 0 | 0 | 30 | 2 | 6 | | | |
| 8 | 2 | 2 | 1 | 31 | 1 | 5 | | | |
| 5 | 5 | 4 | 0 | 32 | 0 | 0 | 2 | | |
| | 7 | 5 | 3 | 33 | 0 | 4 | 8 | 9 | |
| | | 1 | 0 | 34 | 1 | 1 | 3 | 4 | 6 |
| | | | | 35 | 3 | | | | |
| | | | 8 | 36 | 7 | 9 | | | |
Key: 2 | 31 | 5 means \\(31 200 for a Petral employee and
)31500 for a Ravon employee.
- Find the median and the interquartile range of the salaries of the Petral employees.
The median salary of the Ravon employees is \(
) 33800\(, the lower quartile is \)\\( 32000\) and the upper quartile is \(
) 34400$. - Represent the data shown in the back-to-back stem-and-leaf diagram by a pair of box-and-whisker plots in a single diagram.
\includegraphics[max width=\textwidth, alt={}, center]{f979a442-da05-410b-84dc-3da3286514a0-07_707_1395_477_335} - Comment on whether the mean or the median would be a better representation of the data for the employees at Petral.