GCSE Secondary Maths Age 13-17 - Probability & Statistics: Mean - Explained

Mr. Brown gives a test to his class, where the girls have a mean mark of 70% and the boys 80%. Nick incorrectly assumes the overall mean is 75%. The teacher calculates the correct mean as 76% by finding the total marks for girls and boys, then dividing by the total number of students. The teacher emphasizes the importance of showing all work and concludes that Nick's assumption is incorrect.

What was Nick's assumption about the mean mark of the class?

• The mean mark is 80.

• The mean mark is 76.

• The mean mark is 75.

• The mean mark is 70.

How many girls are in Mr. Brown's class?

• 25

• 20

• 15

• 10

What is the total mark for the boys in the class?

• 1200

• 1500

• 800

• 700

What is the total number of students in Mr. Brown's class?

• 30

• 35

• 25

• 20

What is the correct overall mean mark for the class?

• 80

• 76

• 75

• 70

Why is it important to show all your work in calculations?

• To ensure you get full marks.

• To make the paper look neat.

• To confuse the examiner.

• To avoid losing marks for unseen work.

What is the significance of the final conclusion in the problem?

• It shows that Nick was correct.

• It justifies that the mean mark is 76.

• It proves the calculation was unnecessary.

• It confirms the mean mark is 75.