Asha scored 72 in a test whose marks have mean 60 and standard deviation 8. Ravi scored 80 in another test with mean 70 and standard deviation 10. Who did better compared with their own class?

Ravi, with the higher scoreCorrect answerYour answerAsha, with

z = 1.5

against 1Correct answerYour answerBoth equally, each 12 or 10 above the meanCorrect answerYour answerRavi, with

z = 1.5

against 1Correct answerYour answer

Show the answer and explanation

CorrectNot quiteAnswer B

Correct answer: B

Asha: $z = \frac{72 - 60}{8} = 1.5$ . Ravi: $z = \frac{80 - 70}{10} = 1$ .
Asha is 1.5 standard deviations above her class, Ravi only 1, so Asha did better.

Worth noting

Ravi's 80 is the higher mark, but marks from different tests can only be compared after standardising.

Ten questions from Normal Distribution, at your own pace.

Explanation