Grouping Data - Worksheet—Answers
1.
An airline company records the weights of the bags that passengers check in (in kg to 1 dp).
7.3
7.0
10.8
7.9
10.5
A)
B)
2.
8.2
8.4
11.2
12.4
9.5
9.1
4.9
13.4
11.6
4.7
9.0
5.4
11.2
9.4
5.6
6.2
6.4
7.8
9.0
7.1
Weight (kg)
6.1
7.9
4.3
6.7
8.2
Copy and complete the grouped frequency table.
What is the modal class?
6≤w<8
Tally
Frequency
4≤w<6
5
6≤w<8
10
8 ≤ w < 10
8
10 ≤ w < 12
5
12 ≤ w < 14
2
Mr Jackson times the students in class 7C doing a Maths puzzle (in seconds to 1dp).
22.5 12.3 6.3 9.9 29.0 22.2 37.0 17.2 17.2 28.4
37.0 29.7 4.1
28.8 27.0 23.8 14.8 10.0 20.0 33.8
30.1 32.2 20.1 21.6 10.5 23.7 36.7 25.5 18.8 25.6
A) Copy and complete the grouped frequency table.
B) What is the modal class?
20 ≤ t < 30
C) The cut off point for Bronze medal was 30 seconds. How many students got a medal?
3 + 7 + 14 = 23
3.
4.
A) Draw a grouped frequency table to sort the
data into groups of 80-100, 100-120 etc.
B) What is the modal group?
80 ≤ L < 100
A) Draw a grouped frequency table to sort the
data into groups.
B) What is the modal class?
40 ≤ w < 60
C) What is the range of weights? 120 - 40 = 80
D) What could you say about the weight of
adults from the data?
Adults have a variety of weights but do not
often weigh over 100kg.
Time (s)
Tally
Frequency
0 ≤ t < 10
3
10 ≤ t < 20
7
20 ≤ t < 30
14
30 ≤ t < 40
6
Length (mins)
Tally
Frequency
80 ≤ L < 100
15
100 ≤ L < 120
13
120 ≤ L < 140
9
140 ≤ L < 160
1
160 ≤ L < 180
2
Weight (kg)
Tally
Frequency
40 ≤ w < 60
11
60 ≤ w < 80
8
80 ≤ w < 100
10
100 ≤ w < 120
1
Challenge Question
Neil measured the weight of crisps in 30 bags.
The bags were marked ‘Average contents 25g’.
He used a very accurate electronic balance. Here are his results in
grams:
24.498
25.571
25.367
24.759
24.968
26.254
24.531
25.274
25.148
24.589
25.374
23.987
25.014
24.985
25.178
26.010
25.984
24.591
25.367
24.361
24.257
25.451
26.357
24.367
24.487
25.184
24.568
24.856
24.168
25.684
A) Draw a grouped frequency
table to sort the data.
Weight (g)
Tally
Frequency
23.5 ≤ w < 24.5
7
24.5 ≤ w < 25.5
17
25.5 ≤ w < 26.5
6
B) Is the average contents claim correct?
As you can see from the table, the claim is correct.