Collect, Organise & Summarise Data (Grade 9) — Worksheet & Memo

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Grade 9 · Data Handling

Collect, Organise & Summarise Data (Grade 9)

WORKSHEET

Name:

Class:

Date:

Mark

/ 36

Answer all questions. Show all your working — marks are awarded for method as well as the final answer.

1
The mean of 45, 52, 61, 48, 54 and x is 52. Solve for x.
(3)
2
What is the difference between a population and a sample?
(2)
3
Why is surveying only your friends about school food biased?
(2)
4
What is wrong with the intervals 0–10, 10–20, 20–30?
(2)
5
How do a histogram and a bar graph differ?
(2)
6
In the histogram above, which is the modal class?
(1)
7
In the histogram above, how many values are there in total?
(2)
8
Find the mean of R8 000, R9 000, R9 500, R10 000 and R80 000.
(3)
9
Find the median of that same salary data.
(2)
10
Which average is fairer for that salary data, and why?
(2)
11
Give TWO reasons why a double bar graph is better than two separate bar graphs for comparing boys and girls.
(2)
12
The double bar graph below shows the sports played by a group of learners. State the difference between the number of girls and the number of boys who play netball, and one thing the graph does NOT tell you.
(2)
13
Explain how two separate bar graphs could be used to mislead a reader.
(2)
14
In a spelling test the boys’ mean was 71% and the girls’ mean was 78%. Write a conclusion that would earn full marks.
(2)
15
A shop’s sales were 48, 54, 60 and 66 items over four weeks. Predict week 5 and state the assumption you are making.
(3)
16
A learner surveys 20 friends and reports that “most learners at the school play soccer”. Give TWO reasons to question this conclusion.
(2)
17
A bar graph’s vertical axis starts at 40 instead of 0. Explain how this could mislead a reader.
(2)

TOTAL: 36 marks