Page 106 - MAT KS3 Y8 Cambridge CheckPoint

10.1 Calculating statistics from discrete data

3 Hassan recorded the number of people in 60 passing cars.
Here are his results. Find:
a the missing frequency People 1 2 3 4 5 6
b the modal number of people in a car Frequency 28 3 7 1 1
c the median d the mean.

4 Oditi throws two dice and adds the scores.
She does this 36 times. Here are the results.
Find:
a the mode b the median Score 2 3 4 5 6 7 8 9 10 11 12
c the mean d the range. Frequency 3 0 2 4 5 4 6 8 1 1 2

5 A quiz has 10 questions. 120 students take the quiz.
The table shows their scores.

Questions answered correctly 4 5 6 7 8 9 10
Frequency 3 5 12 13 17 30 40

How many students scored:
a more than the median b more than the mode c more than the mean?

6 This table shows the results of 60 throws of a biased dice. Read what Ahmad, Harsha and Alicia say.

Score 1 2 3 4 5 6
Frequency 11 9 10 8 19 3

The average is 3.4.
The average is 3.5. The average is 5.
Explain how Ahmad, Harsha and Alicia could all be correct.
a could all be correct
7 The table shows the ages of 50 members of a club.
Age 11 12 13 14 15 16
a Find: i the mean age ii the median age
iii the modal age iv the age range Frequency 10 21 8 5 3 3
b Read what Dakarai says.
Is he correct?
In one year’s time the mean, the median, the mode and
the range for these 50 people will all increase by 1.

8 This table shows the number of goals scored by a football club in each match in one season.
a Find: i the number of games played
Goals 0 1 2 3 4 5 6 7 8
ii the mode iii the median
Frequency 6 11 5 11 4 0 2 0 1
iv the mean number of goals.
b Maha asked: ‘What is the average number of goals?’
Which would be the best average to use to answer this question? Give a reason for your answer.

9 Twenty people each choose a number, from a choice of
1, 2, 3, 4 or 5. Number 1 2 3 4 5
The mode is larger than the median. Frequency
The median is larger than the mean.
Copy the table. Fill in a set of possible frequencies.
104 10 Processing and presenting data