Question

Last week, Sarah had exams in Math, Spanish, and English. On the Math exam, the mean was µ = 30 with s = 5, and Sarah had a score of X = 45. On the Spanish exam, the mean was µ = 60 with s = 8 and Sarah had a score of X = 68. On the English exam, the mean was µ = 70 with s = 8 and Sarah had a score of X = 70. For which class should Sara expect the better grade?​

Answer 1

Sara expect the better grade for Math class.

Step-by-step explanation:

Consider the provided information.

On the Math exam, the mean was µ = 30 with s = 5, and Sarah had a score of X = 45.

Z score for Math:
`Z=(x-\mu)/(s)`

`Z=(45-30)/(5)`

`Z=(15)/(5)`

`Z=3`

On the Spanish exam, the mean was µ = 60 with s = 8 and Sarah had a score of X = 68.

Z score for Spanish:
`Z=(x-\mu)/(s)`

`Z=(68-60)/(8)`

`Z=(8)/(8)`

`Z=1`

On the English exam, the mean was µ = 70 with s = 8 and Sarah had a score of X = 70.

Z score for English:
`Z=(x-\mu)/(s)`

`Z=(70-70)/(8)`

`Z=0`

We can observe that Z score of Math is greater than Spanish and English.

Which means that Sarah did the best in her Math exam.

Hence, Sara expect the better grade for Math class.