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End-of-unit review

End-of-unit review

1 Anders spins a coin until he gets a head, then writes 2 2 2 1 3 1 1 1 2 2 1 2
down the number of spins he tried. He does this 24 times. His
results are shown on the right. 5 1 1 1 1 1 2 3 2 1 3 1
Work out:
a the modal number of spins b the median c the mean d the range.
2 Sasha uses a spreadsheet to simulate the coin-spinning activity described in question 1.
She records her results in a table.

Spins to get a head 1 2 3 4 5 6 7 8 9
Frequency 160 75 44 18 10 5 2 0 1
Work out: a the modal number of spins b the median c the mean d the range.

3 Here are the ages of children in a kindergarden. Age 3 4 5 6
Work out:
a the median age of the girls Girls 6 14 16 2
b the mean age of the boys Boys 1 13 6 4
c the modal age of all the children.
4 A group of children and a group of adults estimate the number of sweets in a jar.

Number of sweets 60−64 65−69 70−74 75−79 80−84 85−89

Children 6 13 21 15 5 0
Adults 2 8 19 31 20 20
There are 73 sweets in the jar. Who are the best estimators, children or adults?
Use the appropriate statistics to justify your answer.

5 A snack bar sells two different cold drinks, Coola and Freezy.
Here are the sales each day for a week.

Day Monday Tuesday Wednesday Thursday Friday Saturday Sunday
Coola 42 58 63 39 74 75 38

Freezy 81 75 63 42 55 25 89
Work out statistics to compare the sales of each drink.

6 When you play darts, you throw three darts at the board and add the scores.
Bristoe and Clancey are practising. Here are their scores for a number of turns.
Bristoe 18, 32, 26, 53, 5, 29, 41, 15, 85, 9, 44, 28, 100, 37, 55

Clancey 41, 26, 33, 51, 26, 29, 60, 45, 60, 19, 42, 36
a Who has the better average score? Give a reason for your answer.
b Who has the more varied scores? Give a reason for your answer.

102 10 Processing and presenting data