Class A and Class B both have a mean test mark of 62. Class A has a standard deviation of 4 and Class B has 11. Which statement is correct?
Answer and explanation
Correct answer: D. Class A's marks are more consistent
- Step 1: A smaller standard deviation means the marks are closer to the mean.
- Step 2: So Class A is more consistent.
Answer
Class A's marks are more consistent.
Why not the others: Class B's marks are more consistent: a larger standard deviation means more spread. Class B did better on average: the means are equal. Class A had the highest individual mark: standard deviation does not give the highest mark.
Practise more Trigonometry, Vectors, Statistics and Applications.
Free questions with an explanation for every one, and full timed National 5 (Scotland) mock tests.