Robinson Tuition
Grade 3 · Foundation · free GCSE maths worksheet

Plotting scatter graphs

Drawing points and describing correlation.

14 original questions, 36 marks. Print the worksheet, mark it with the answers sheet, and use the solutions to see every step written out by hand.

Worksheet PDFWorked solutions PDFAnswers PDF

The questions

1

The table shows the height and shoe size of some students.

StudentHeight (cm)Shoe size
Anna1504
Ben1626
Chen1718
Dina1585

Anna draws a scatter graph with height on the horizontal axis and shoe size on the vertical axis.

Write down the coordinates of the points she should plot for Ben and for Chen.

2 marks
Show answer
Ben) (162, 6) Chen) (171, 8)
2

Write down the type of correlation you would expect to see in a scatter graph of each of the following.

  1. The daily temperature and the number of ice creams sold at a kiosk.
  2. The age of a car and its value.
2 marks
Show answer
a) positive correlation b) negative correlation
3

A scatter graph shows the maths score (horizontal axis) and the science score (vertical axis) of some students. One point on the graph is at (35, 40).

Write down what this point tells you about this student.

2 marks
Show answer
The student scored 35 in maths and 40 in science
4

The table shows the number of hours that each of 8 students spent revising, and their scores in a test.

Hours revising12345678
Test score2228353947525865

The data is plotted on a scatter graph.

  1. Describe the type of correlation the scatter graph would show.
  2. Interpret this correlation for these students.
0123456789010203040506070Hours revisingTest score
2 marks
Show answer
a) positive correlation b) Students who spent longer revising scored higher marks
5

Zoe has drawn a scatter graph and wants to add a line of best fit.

Describe how a line of best fit should be drawn.

2 marks
Show answer
A straight line passing close to the points, with roughly equal numbers of points above and below it, following the trend of the points
6

The table shows the age and the value of six second-hand cars of the same model.

Age (years)124578
Value (£1000)13119853

On the grid, plot the information in the table as a scatter graph.

0123456789100246810121416Age (years)Value (£1000)
2 marks
Show answer
Crosses plotted at (1, 13), (2, 11), (4, 9), (5, 8), (7, 5), (8, 3)
7

The table shows the hours of television 6 students watched in a week and their scores in a test.

Hours of TV258101416
Test score787061554438
  1. What type of correlation would a scatter graph of this data show?
  2. Write a sentence to describe what this correlation tells you.
2 marks
Show answer
a) negative correlation b) the more television a student watches, the lower their test score tends to be
8

The table shows the shoe size and the maths mark of 8 students.

Shoe size496758310
Maths mark6240557035664852

Jade says there is no correlation between shoe size and maths mark.

Is Jade correct? Give a reason.

2 marks
Show answer
Yes. The marks do not go up or down with shoe size - there is no pattern
9

The scatter graph shows the number of hours of sunshine and the number of visitors to a country park on each of 10 days.

  1. Describe the correlation shown by the scatter graph.
  2. On another day there were 7.5 hours of sunshine. By drawing a line of best fit, estimate the number of visitors to the park on this day.
0123456789101112020406080100120140160180200220240Hours of sunshineNumber of visitors
3 marks
Show answer
a) positive correlation b) approximately 160 (accept 150-175)
10

The scatter graph shows the number of hours ten students revised and their scores in a test.

  1. Draw a line of best fit on the scatter graph.
  2. Use your line of best fit to estimate the test score of a student who revised for 6.5 hours.
0123456789100102030405060708090100Hours revisedTest score
3 marks
Show answer
a) A straight line close to the points, with about as many points above as below, e.g. from (0, 15) to (10, 85) b) About 60 (accept 56 to 64 if it matches their line)
11

A scatter graph shows the hours revised (from 1 to 9 hours) and the test score of some students. The line of best fit passes through (0, 10) and (10, 60).

  1. Use the line to estimate the test score of a student who revised for 7 hours.
  2. Explain why the line should not be used to estimate the score of a student who revised for 25 hours.
3 marks
Show answer
a) 45 b) 25 hours is outside the range of the data, so the estimate is unreliable
12

The table shows the maths score and the science score of 8 students.

Maths score1020253035404550
Science score1826323840445054

The first six points have been plotted on the scatter graph.

  1. Complete the scatter graph by plotting the last two points.
  2. Describe the correlation between the maths scores and the science scores.
  3. Interpret this correlation.
051015202530354045505560051015202530354045505560Maths scoreScience score
3 marks
Show answer
a) (45,50) and (50,54) plotted correctly b) positive correlation c) The higher a student's maths score, the higher their science score tends to be
13

The table shows the temperature at noon and the number of ice creams sold at a kiosk on 8 days.

Temperature (°C)1416182022242628
Ice creams sold2833394520566268
  1. Write down the coordinates of the outlier.
  2. Write down the type of correlation shown by the other points.
  3. A line of best fit passes through (14, 28) and (28, 68). Use it to estimate the number of ice creams sold when the temperature is 21°C.
4 marks
Show answer
a) (22, 20) b) positive correlation c) 48
14

The table shows the age, in years, and the resale value, in pounds, of 8 laptops of the same model.

Age (years)122.5344.556
Value (£)52046043038030090210150

The data is plotted on a scatter graph.

  1. Describe the correlation between the age of a laptop and its value.
  2. One laptop does not fit the general trend. Which laptop is this?
  3. Interpret the correlation for these laptops.
  4. Give a reason why the scatter graph should not be used to estimate the value of a 10 year old laptop.
012345670100200300400500600Age (years)Value (£)
4 marks
Show answer
a) negative correlation b) the 4.5 year old laptop at £90 c) As laptops get older their value decreases d) 10 years is outside the range of the data (1 to 6 years), so the trend may not continue

Every question here is original and written by Robinson Tuition. The grade follows the Edexcel grade descriptors and suits AQA and OCR too; this is not an exam-board paper.

All Grade 3 topics