AI generatedStatisticsGCSE Higher / IGCSE Extended

Calculating class width

Calculating class width.

  • Class width = upper class boundary − lower class boundary.
  • Find each width separately; classes do not have to be equal.
  • For measurements rounded to whole units, convert stated integer limits to boundaries using half a unit.

Example 1

Find the width of the class .

Class widthUpper boundary minus lower boundary. The inequality symbols do not change the width.

Example 2

Lengths are recorded to the nearest centimetre. A class contains recorded lengths 10–14 cm inclusive. Find the class width for a histogram.

Lower boundarySubtract 0.5 from the lowest recorded whole-centimetre value.
Upper boundaryAdd 0.5 to the highest recorded whole-centimetre value.
Class widthSubtract the class boundaries, not the first and last recorded integers.

Your turn

Question 1

Find the width of the class .

Check answer
Class widthUpper boundary minus lower boundary. The inequality symbols do not change the width.
Question 2

Find the width of the class .

Check answer
Class widthUpper boundary minus lower boundary. The inequality symbols do not change the width.
Question 3

Lengths are recorded to the nearest centimetre. A class contains recorded lengths 15–19 cm inclusive. Find the class width for a histogram.

Check answer
Lower boundarySubtract 0.5 from the lowest recorded whole-centimetre value.
Upper boundaryAdd 0.5 to the highest recorded whole-centimetre value.
Class widthSubtract the class boundaries, not the first and last recorded integers.
Question 4

Find the width of the class .

Check answer
Class widthUpper boundary minus lower boundary. The inequality symbols do not change the width.
Question 5

Find the width of the class .

Check answer
Class widthUpper boundary minus lower boundary. The inequality symbols do not change the width.
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