Edexcel S1 — Question 5

Exam BoardEdexcel
ModuleS1 (Statistics 1)
TopicMeasures of Location and Spread
TypeFind median and quartiles from stem-and-leaf diagram

5. In a survey unemployed people were asked how many months it had been, to the nearest month, since they were last employed on a full-time basis. The data collected is summarised in this stem and leaf diagram.
Number of months(2 | 1 means 21 months)Totals
011224446779(11)
102355689( )
21568( )
3079( )
45( )
527(2)
63(1)
70(1)
  1. Write down the values needed to complete the totals column on the stem and leaf diagram.
  2. State the mode of these data.
  3. Find the median and quartiles of these data. Given that any values outside of the limits \(\mathrm { Q } _ { 1 } - 1.5 \left( \mathrm { Q } _ { 3 } - \mathrm { Q } _ { 1 } \right)\) and \(\mathrm { Q } _ { 3 } + 1.5 \left( \mathrm { Q } _ { 3 } - \mathrm { Q } _ { 1 } \right)\) are to be regarded as outliers,
  4. determine if there are any outliers in these data,
  5. draw a box plot representing these data on graph paper,
  6. describe the skewness of these data and suggest a reason for it.