Higher November 2024 Paper 1 Q16
16 When \(w\) is truncated the answer is 8
Sacha writes the error interval due to truncation as \(\quad 7.5 \leqslant w \lt 8.5\)
Give a reason why Sacha is wrong and state the correct error interval for \(w\). [2 marks]
Correct error interval \(\quad \ldots\ldots\ldots \leqslant w \lt \ldots\ldots\ldots\)
| Answer | Mark | Comments |
|---|---|---|
| Valid reason | B1 | see examples below |
| \(8 \leqslant w \lt 9\) | B1 | condone \(8.\dot{9}\) for 9 |
Additional guidance
| Reasons | |
| These are the bounds for rounding to 8 | B1 |
| This is the error interval for the nearest whole number | B1 |
| The number must begin with 8 for it to truncate to 8 | B1 |
| The number cannot be less than 8 | B1 |
| When a number is truncated it gets smaller | B1 |
| \(w\) is being made lower, not higher | B1 |
| When a number is truncated the decimals are removed | B1 |
| The values have to be whole numbers/the bounds shouldn’t be decimals (with no decimals in their bounds) | B1 |
| 7.5 would truncate to 7 | B1 |
| 7.5 is wrong with 8 given as the correct lower bound or 8.5 is wrong with 9 given as the correct upper bound | B1 |
| 7.5 is wrong or 8.5 is wrong without the appropriate correct bound | B0 |