The figure shows two normal curves, A and B, with the same mean. Which statement is true? Two bell-shaped normal curves with the same centre: curve A is tall and narrow, curve B is lower and wider.

The figure shows two normal curves, A and B,…

The figure shows two normal curves, A and B, with the same mean.

Question 7

MediumOriginal question

The figure shows two normal curves, A and B, with the same mean. Which statement is true?

Two bell-shaped normal curves with the same centre: curve A is tall and narrow, curve B is lower and wider.

A has the larger standard deviationCorrect answerYour answerA has the larger total areaCorrect answerYour answerB has the larger standard deviationCorrect answerYour answerB has the larger meanCorrect answerYour answer

Show the answer and explanation

CorrectNot quiteAnswer C

Correct answer: C

Both curves enclose an area of 1, so a wider curve must be lower.
B is lower and more spread out, so its standard deviation is larger.

Worth noting

A is taller, but height shows how bunched the values are: a taller curve has the smaller spread.

Concept: Reading the spread from the curve
Typical timeTypical: 90 s
Your timeYours: —

The rule this testsThe normal curve

Practise this chapter →

Ten questions from Normal Distribution, at your own pace.

Practise this chapter →

Ten questions from Normal Distribution, at your own pace.

The figure shows two normal curves, A and B, with the same mean.

Question 7

Explanation