Mathematics 9709 · AS & A Level · Representation of data
Representation of data — practice question
The weights, $x$ kg, of 120 students at a sports college are measured and recorded. The results are presented in the table below: Weight ($x$ kg): $x \leq 40,\ x \leq 60,\ x \leq 65,\ x \leq 70,\ x \leq 85,\ x \leq 100$. Cumulative frequency: $0, 14, 38, 60, 106, 120$.
(a)[2]
Draw a cumulative frequency graph to display this information.
(b)[2]
It is given that $35\%$ of the students have a weight greater than $W$ kg. Use your graph to estimate the value of $W$.
(c)[6]
Calculate estimates of the mean and standard deviation for the weights of the 120 students.
Worked solution & mark scheme
This 10-mark question has a full step-by-step worked solution and mark scheme. One marking point: “At least three cumulative frequency points are plotted accurately at the upper ends of the classes.” …