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

Answer:

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: $Z=\frac{x-\mu}{s}$

$Z=\frac{45-30}{5}$

$Z=\frac{15}{5}$

$Z=3$

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

Z score for Spanish: $Z=\frac{x-\mu}{s}$

$Z=\frac{68-60}{8}$

$Z=\frac{8}{8}$

$Z=1$

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

Z score for English: $Z=\frac{x-\mu}{s}$

$Z=\frac{70-70}{8}$

$Z=0$

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.