1MA0 Higher June 2016 Paper 2 Q10
10 The table gives information about the heights of 50 trees.
| Height (\(h\) metres) | Frequency |
|---|---|
| \(0 \lt h \leqslant 4\) | 8 |
| \(4 \lt h \leqslant 8\) | 21 |
| \(8 \lt h \leqslant 12\) | 12 |
| \(12 \lt h \leqslant 16\) | 7 |
| \(16 \lt h \leqslant 20\) | 2 |
Work out an estimate for the mean height of the trees. (4)
| Working | Answer | Mark | Notes |
|---|---|---|---|
| \(2 \times 8 = 16\) \(6 \times 21 = 126\) \(10 \times 12 = 120\) \(14 \times 7 = 98\) \(18 \times 2 = 36\) | 7.92 | 4 | M1 for \(fx\) with \(x\) consistently within interval including ends (allow 1 error) M1 for consistently using appropriate midpoints in \(fx\) M1 (dep on first M1) for \(\text{``}\Sigma fx\text{''} \div 50\) (or divided by \(\text{``}\Sigma f\text{''}\) if clearly calculated), eg \(396 \div 50\) A1 for 7.92 cao |