Edexcel S1 2012 June — Question 5

Exam BoardEdexcel
ModuleS1 (Statistics 1)
Year2012
SessionJune
TopicData representation
TypeDirect frequency calculation from histogram

5. \begin{figure}[h]
\includegraphics[alt={},max width=\textwidth]{0593544d-392d-465b-b922-c9cb1435abb5-08_1031_1239_116_354} \captionsetup{labelformat=empty} \caption{Figure 2}
\end{figure} A policeman records the speed of the traffic on a busy road with a 30 mph speed limit. He records the speeds of a sample of 450 cars. The histogram in Figure 2 represents the results.
  1. Calculate the number of cars that were exceeding the speed limit by at least 5 mph in the sample.
  2. Estimate the value of the mean speed of the cars in the sample.
  3. Estimate, to 1 decimal place, the value of the median speed of the cars in the sample.
  4. Comment on the shape of the distribution. Give a reason for your answer.
  5. State, with a reason, whether the estimate of the mean or the median is a better representation of the average speed of the traffic on the road.