Histograms, stem and leaf diagrams and box plotsEdexcel International A Level Maths: Mind map

Exam questions on Histograms, stem and leaf diagrams and box plots

1. The lengths of 60 phone calls are grouped as follows: 12 calls lasted from 0 to 2 minutes, 21 calls from 2 to 5 minutes, 15 calls from 5 to 10 minutes, and 12 calls from 10 to 20 minutes. A histogram is drawn with frequency density on the vertical axis.
   In the histogram, the bar for the class 2 to 5 minutes is 3.5 cm tall. Find the height of the bar for the class 10 to 20 minutes.2 marks
2. The scores of 15 players in a game are 23, 27, 31, 34, 34, 38, 41, 42, 45, 47, 52, 53, 58, 61 and 66. They are shown in an ordered stem and leaf diagram.
   Describe the skewness of the distribution, justifying your answer using the quartiles.2 marks
3. The times, in seconds, taken by 12 boys and 12 girls to complete an obstacle course are shown in a back-to-back stem and leaf diagram. The boys' times are 41, 43, 45, 47, 48, 52, 54, 55, 58, 61, 63 and 69. The girls' times are 38, 40, 42, 44, 45, 46, 49, 51, 53, 55, 57 and 62.
   Find the median and the interquartile range of the girls' times.3 marks