Edexcel S1 — Question 5

Exam BoardEdexcel
ModuleS1 (Statistics 1)
TopicMeasures of Location and Spread
TypeCoding to simplify calculation

5. An antiques shop recorded the value of items stolen to the nearest pound during each week for a year giving the data in the table below.
Value of goods stolen (£)Number of weeks
0-19931
200-3996
400-5993
600-7994
800-9995
1000-19992
2000-29991
Letting \(x\) represent the mid-point of each group and using the coding \(y = \frac { x - 699.5 } { 200 }\),
  1. find \(\sum\) fy.
  2. estimate to the nearest pound the mean and standard deviation of the value of the goods stolen each week using your value for \(\sum f y\) and \(\sum f y ^ { 2 } = 424\).
    (6 marks)
    The median for these data is \(\pounds 82\).
  3. Explain why the manager of the shop might be reluctant to use either the mean or the median in summarising these data.
    (3 marks)