Statistical questions, dot plots and histograms
Answers are for parents and teachers.
1
Write one statistical question and one question that is not statistical about the pupils of your class.
For example: “How many pencils does each pupil have?” (statistical) and “What is the name of our teacher?” (not statistical).
2
The data are 1, 2, 2, 3, 3, 3, 4, 4, 6. Draw a dot plot. Where is the peak and where is the gap?
Dots: 1 has 1, 2 has 2, 3 has 3, 4 has 2, 5 has 0, 6 has 1. The peak is at 3 and the gap is at 5.
3
This histogram shows the number of letters in the first names of 20 pupils. How many names have 5 letters or more? Which interval is the tallest?
The intervals 5–6 and 7–8 together: 8 + 3 = 11 names. The tallest interval is 5–6 with 8 names. Check: 2 + 7 + 8 + 3 = 20.
4
Sort these 10 ages of cousins into the intervals 0–4, 5–9, 10–14, 15–19: 4, 7, 12, 15, 9, 3, 18, 11, 6, 13.
0–4: 2 (4, 3). 5–9: 3 (7, 9, 6). 10–14: 3 (12, 11, 13). 15–19: 2 (15, 18). Check: 2 + 3 + 3 + 2 = 10.
5
Explain two differences between a bar graph and a histogram.
A bar graph shows categories and has gaps between bars. A histogram shows numbers grouped into equal intervals and its bars touch.