OCR MEI S1 2008 January — Question 1

Exam BoardOCR MEI
ModuleS1 (Statistics 1)
Year2008
SessionJanuary
TopicMeasures of Location and Spread
TypeFind median and quartiles from stem-and-leaf diagram

1 Alice carries out a survey of the 28 students in her class to find how many text messages each sent on the previous day. Her results are shown in the stem and leaf diagram.
000113577788
1012334469
201337
357
4
58
Key: 2 | 3 represents 23
  1. Find the mode and median of the number of text messages.
  2. Identify the type of skewness of the distribution.
  3. Alice is considering whether to use the mean or the median as a measure of central tendency for these data.
    (A) In view of the skewness of the distribution, state whether Alice should choose the mean or the median.
    (B) What other feature of the distribution confirms Alice's choice?
  4. The mean number of text messages is 14.75 . If each message costs 10 pence, find the total cost of all of these messages.