4 The following are the house prices in thousands of dollars, arranged in ascending order, for 51 houses from a certain area.
| 253 | 270 | 310 | 354 | 386 | 428 | 433 | 468 | 472 | 477 | 485 | 520 | 520 | 524 | 526 | 531 | 535 |
| 536 | 538 | 541 | 543 | 546 | 548 | 549 | 551 | 554 | 572 | 583 | 590 | 605 | 614 | 638 | 649 | 652 |
| 666 | 670 | 682 | 684 | 690 | 710 | 725 | 726 | 731 | 734 | 745 | 760 | 800 | 854 | 863 | 957 | 986 |
- Draw a box-and-whisker plot to represent the data.
An expensive house is defined as a house which has a price that is more than 1.5 times the interquartile range above the upper quartile.
- For the above data, give the prices of the expensive houses.
- Give one disadvantage of using a box-and-whisker plot rather than a stem-and-leaf diagram to represent this set of data.