Question 1 Report
The table shows the weights, to the nearest kilogram, of twelve students in a Further Mathematics class
| Weight in kg | 55 | 57 | 59 | 61 | 63 |
| No of students | 2 | 1 | 2 | 4 | 3 |
(a) Draw a bar chart to illustrate the above information;
(b) What is (i) the mode; (ii) the median of the distribution?
(c) Calculate the mean weight correct to the nearest kilogram.
(a) Bar chart
(b)(i) Mode
The highest frequency is 4, corresponding to a weight of 61 kg.
\[\boxed{\text{Mode}=61\text{ kg}}\]
(b)(ii) Median
There are \(12\) students. Therefore, the median is the mean of the 6th and 7th observations.
The ordered weights are:
\[55,\ 55,\ 57,\ 59,\ 59,\ \underbrace{61,\ 61}_{\text{6th and 7th}},\ 61,\ 61,\ 63,\ 63,\ 63\]
\[\text{Median}=\frac{61+61}{2}=\boxed{61\text{ kg}}\]
(c) Mean weight
\[\begin{aligned}\sum f&=2+1+2+4+3=12,\\\sum fx&=55(2)+57(1)+59(2)+61(4)+63(3)\\&=110+57+118+244+189\\&=718.\end{aligned}\]
\[\text{Mean}=\frac{\sum fx}{\sum f}=\frac{718}{12}=59.833\ldots\text{ kg}\]
\[\boxed{\text{Mean weight}=60\text{ kg, correct to the nearest kilogram}}\]
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