Statistics worksheet — GCSE Foundation

1.A school has 1200 pupils. A teacher wants to take a random sample of 60 of them. Write down which of these methods gives a random sample.

2.A council wants to find out what all residents of a town think about a new cycle lane. It posts a survey only on its website and asks people to fill it in online. Give a reason why this sample is likely to be biased.

3.The mean of three numbers is 50. A fourth number, 100, is added to the set. Work out the mean of the four numbers.

4.Write down the statement that correctly describes the difference between correlation and causation.

5.A school has 1,500 pupils. The head teacher takes a random sample of 150 of them from the school register and asks how long they spend on homework. Rory says the sample is too small for the result to mean anything. Is Rory right? Give a reason for your answer.

6.Four pairs of variables are listed below. Write down the pair that you would expect to show no correlation.

7.A café in Preston records the type of drink ordered by 20 customers one morning: tea 8, coffee 7, hot chocolate 4 and juice 1. Write down the modal drink.

8.Seven pupils were asked how many books they had read last month. Their answers were 3, 5, 5, 7, 8, 5, 3. Write down the mode.

9.A Year 10 class has 20 boys with a mean height of 150 cm and 10 girls with a mean height of 168 cm. Work out the mean height of all 30 pupils in the class.

10.A garden centre's sales, in thousands of pounds, at the end of each quarter last year were: quarter 1 — 18, quarter 2 — 34, quarter 3 — 30, quarter 4 — 22. Work out the increase in sales from quarter 1 to the quarter with the highest sales.

11.Grace asked 12 children how many brothers and sisters they have. Her results, in order, were 0, 0, 1, 1, 1, 1, 2, 2, 3, 3, 4, 6. Work out the median number of brothers and sisters.

12.The table shows the times, t minutes, that 30 pupils took to walk to school. 0 < t ≤ 10: 8 pupils. 10 < t ≤ 20: 12 pupils. 20 < t ≤ 30: 6 pupils. 30 < t ≤ 40: 4 pupils. Write down which average can be given exactly from this table, and give a reason for your answer.

13.A dual bar chart shows how many boys and how many girls are in a class. The bar for boys stands at 14 and the bar for girls stands at 16. Work out how many pupils are in the class altogether.

14.A straight line is drawn on a scatter graph to show the trend of the points. Write down the name given to this line.

15.A shop records the colour of every car that uses its car park one Tuesday. Its frequency table reads: black 44, silver 37, blue 26, red 18, white 12. Write down the frequency of black cars.