Solve mixed data cases: compare pockets, quiz scores and Sudoku times, split a class at the median, and check claims about skyscrapers.
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Compare spread, centre and extremes, not just one number.
Which statements about boys' and girls' pockets are true?
Problem. The dot plots show the number of pockets on clothing for a group of boys and a group of girls. Which statements are true? (Textbook p. 129, Q1)
Compare two groups with mean and median.
Figure it Out, Textbook p. 130, Q3. General Knowledge quiz marks (out of 100):
Group 1: 85, 76, 90, 85, 39, 48, 56, 95, 81, 75
Group 2: 68, 59, 73, 86, 47, 79, 90, 93, 86
Q10, p. 132. Aditi's times (seconds) to solve 'Easy' Sudoku puzzles:
Week 1: 410, 400, 370, 340, 360, 400, 320, 330, 310
Week 2: 320, 290, 380, 280, 270, 230, 220, 240
Compare and describe each pair using the mean and median. (Sketch a dot plot from 200 to 420 for the Sudoku times.)
Sort first.
Any low scores pulling a mean down?
Sort first.
Did Aditi improve?
Median splits and what a mean can't tell you.
17 heights (cm): 106, 110, 123, 125, 117, 120, 112, 115, 110, 120, 115, 102, 115, 115, 109, 115, 101. What is the median? (Textbook p. 130, Q5)
Estimate from bar lengths, and check what the chart does NOT show.
The book shows an infographic of the cities with the most skyscrapers (buildings taller than 150 m). Some bars carry numbers; others must be estimated by comparing their lengths.
Estimating unlabelled bars and checking three claims.
Problem. Estimate the number of skyscrapers in New York, Tokyo and London, and judge three claims. (Textbook p. 131, Q8)
Estimate and judge from the skyscraper chart.
New York's bar is a little shorter than Shenzhen's (367). About how many skyscrapers?