Edexcel S1 — Question 5

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

5. For a project, a student asked 40 people to draw two straight lines with what they thought was an angle of \(75 ^ { \circ }\) between them, using just a ruler and a pencil. She then measured the size of the angles that had been drawn and her data are summarised in this stem and leaf diagram.
Angle( \(6 \mid 4\) means \(64 ^ { \circ }\) )Totals
41(1)
4(0)
5024(3)
5589(3)
611334(5)
655789(5)
7011233444(9)
75667799(7)
801134(5)
856(2)
  1. 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,
  2. determine if there are any outliers in these data,
  3. draw a box plot representing these data on graph paper,
  4. describe the skewness of the distribution and suggest a reason for it.