Page 183 - MAT KS3 Y8 Cambridge CheckPoint

18.1 Interpreting and drawing frequency diagrams

3 The frequency table shows the number of cups Number of cups of coffee sold Frequency
of coffee sold each day in a coffee shop during 0–19 2
one month.
a Draw a frequency diagram to show the data. 20–39 3
b Which month do you think your frequency 40–59 6
diagram represents? Explain your answer. 60–79 12
c Read what Jake says. 80–99 5

The frequency diagram shows that that the most
cups of coffee sold was 99.

Is he correct? Explain your answer.
4 The frequency table shows the speeds of cars passing Speed of car, s (km/h) Frequency
a speed camera on one day. The speeds are recorded 50 < s ⩽ 60 2
in kilometres per hour (km/h).
60 < s ⩽ 70 3
a Draw a frequency diagram to show the data.
b The speed limit is 80 km/h. How many cars were 70 < s ⩽ 80 6
travelling over the speed limit? 80 < s ⩽ 90 12
c Read what Harsha says.
90 < s ⩽ 100 5

The frequency diagram shows that that slowest car
was travelling at 50 km/h.

Is she correct? Explain your answer.

5 Here are the heights, in centimetres, of some plants.

25 32 30 26 34 22 33 34 31 28
39 20 27 33 37 32 25 24 30 29
a Draw a frequency diagram to show the data.
Use the class intervals 20 ⩽ h < 25, 25 ⩽ h < 30, 30 ⩽ h < 35 and 35 ⩽ h < 40.
b How many of the plants are at least 25 cm high?
Explain how you worked out your answer.

18 Interpreting and discussing results 181