| Dolphins | 62 | 75 | 69 | 82 | 63 | 80 | 65 | 65 | 73 | 82 | 72 |
| Sharks | 68 | 84 | 59 | 70 | 71 | 64 | 77 | 80 | 66 | 74 | 72 |
| \(x\) | 1 | 3 | 5 | 7 |
| \(\mathrm { P } ( X = x )\) | 0.3 | \(a\) | \(b\) | 0.25 |
| Country \(P\) | Country \(Q\) | |
| 5 | 15 | |
| 6 | 2348 | |
| 98764 | 7 | 1345677889 |
| 886653 | 8 | 2367788 |
| 977655542 | 9 | 0224 |
| 54431 | 10 | 45 |
| 150 | 350 | 450 | 578 | 595 | 644 | 722 | 798 | 802 | 904 |
| 1000 | 1330 | 1533 | 1561 | 1778 | 1960 | 2167 | 2330 | 2433 | 3231 |
| \(x\) | 1 | 2 | 3 | 4 |
| \(\mathrm { P } ( X = x )\) | \(3 c\) | \(4 c\) | \(5 c\) | \(6 c\) |
| Length of car \(( x\) metres \()\) | Frequency | Frequency density |
| \(2.80 \leqslant x < 3.00\) | 17 | 85 |
| \(3.00 \leqslant x < 3.10\) | 24 | 240 |
| \(3.10 \leqslant x < 3.20\) | 19 | 190 |
| \(3.20 \leqslant x < 3.40\) | 8 | \(a\) |