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.

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’.

How do we complete the table?

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

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

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

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

tom@goteachmaths.co.uk Questions? Comments? Suggestions? …or have you found a mistake!? Any feedback would be appreciated . Please feel free to email: tom@goteachmaths.co.uk