1. Grouped Frequency Tables – Averages – Card Complete & Match
In this activity students work individually or in groups to
match questions and answers.
Instead of cutting out cards, students can letter questions and
answers that go together.
A variety of card sizes are included.

2. Printing To print handouts from slides -
Select the slide from the left. Then click:
File > Print > ‘Print Current Slide’
To print multiple slides -
Click on a section title to highlight all those slides,
or press ‘Ctrl’ at the same time as selecting slides to
highlight more than one. Then click:
File > Print > ‘Print Selection’
To print double-sided handouts -
Highlight both slides before using ‘Print Selection’.
Choose ‘Print on Both Sides’ and ‘Flip on Short Edge’.

3. How do we complete the table?

4. We have an estimate for the total,
how do we find an estimate for the mean?

5. Table A
Height, h (cm)
Frequency, f
Mid-Class value, m
f × m
20 < h ≤ 40 7 30
210
40 < h ≤ 60 5 50
250
60 < h ≤ 80 11 70
770
Totals 23
1230
Table B
Height, h (cm)
Frequency, f
Mid-Class value, m
f × m
10 < h ≤ 20 8 15
120
20 < h ≤ 30 3 25 75
30 < h ≤ 40 7 35
245
40 < h ≤ 50 45
135
Totals 21
575
Median class:
40 < h ≤ 60
Estimate
for the mean:
53.5 cm
Modal class:
60 < h ≤ 80
Median class:
20 < h ≤ 30
Estimate
for the mean:
27.4 cm
Modal class:
10 < h ≤ 20
Half Answers

6. Table A
Height, h (cm)
Frequency, f
Mid-Class value, m
f × m
20 < h ≤ 40 7 30
210
40 < h ≤ 60 5 50
250
60 < h ≤ 80 11 70
770
Totals 23
1230
Table B
Height, h (cm)
Frequency, f
Mid-Class value, m
f × m
10 < h ≤ 20 8 15
120
20 < h ≤ 30 3 25 75
30 < h ≤ 40 7 35
245
40 < h ≤ 50 45
135
Totals 21
575
Median class:
40 < h ≤ 60
Estimate
for the mean:
53.5 cm
Modal class:
60 < h ≤ 80
Median class:
20 < h ≤ 30
Estimate
for the mean:
27.4 cm
Modal class:
10 < h ≤ 20
Table C
Height, h (cm)
Frequency, f
Mid-Class value, m
f × m
10 < h ≤ 20 2 15 30
20 < h ≤ 30 3 25 75
30 < h ≤ 40 35
40 < h ≤ 50 5 45
225
50 < h ≤ 60 7 55
385
Totals 17
715
Table D
Height, h (cm)
Frequency, f
Mid-Class value, m
f × m
20 < h ≤ 40 5 30
150
40 < h ≤ 60 7 50
350
60 < h ≤ 80 9 70
630
80 < h ≤ 100 14 90
1260
100 < h ≤ 120 6
110
660
Totals 41
3050
Median class:
40 < h ≤ 50
Estimate
for the mean:
42.1 cm
Modal class:
50 < h ≤ 60
Median class:
60 < h ≤ 80
Estimate
for the mean:
74.4 cm
Modal class:
80 < h ≤ 100

7. Modal class:
80 < h ≤ 100
Estimate
for the mean:
27.4 cm
Median class:
40 < h ≤ 50
Median class:
60 < h ≤ 80
Estimate
for the mean:
53.5 cm
Median class:
20 < h ≤ 30
Median class:
40 < h ≤ 60
Estimate
for the mean:
42.1 cm
Modal class:
60 < h ≤ 80
Modal class:
10 < h ≤ 20
Estimate
for the mean:
74.4 cm
Modal class:
50 < h ≤ 60

9. tom@goteachmaths.co.uk Questions? Comments? Suggestions?
…or have you found a mistake!?
Any feedback would be appreciated .
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