Question

Joshua and Emily each spun a spinner with two coloured

sections a number of times. They recorded how many
times the spinner landed on each colour in the table
below.
a) Calculate the estimated probability of the spinner
landing on purple using
i) Joshua's results.
ii) Emily's results.
Give each of your answers as a decimal.
b) Which person's results give a better estimate for the
probability? Write a sentence to explain your answer.
Colour
Person
Joshua
Emily
Purple
17
11
Black
33
9

Answer 1

a. i) The estimated probability of the spinner landing on purple using Joshua’s results is:

17 / (17 + 33) = 0.34

ii) The estimated probability of the spinner landing on purple using Emily’s results is:

11 / (11 + 9) = 0.55

b. Emily’s results give a better estimate for the probability because she spun the spinner more times than Joshua, so her results are more reliable.

I hope this helps!