Maths B
posted by Anna .
Charlotte received a score of 68 on both her English and Maths tests. The mean for English was 52 and the mean for Maths was 55. The standard deviations for English and Maths
were 10 and 8 respectively. In which subject did Charlotte perform better? Explain your
decision.

Z = (scoremean)/SD
Find table in the back of your statistics text labeled something like "areas under normal distribution" to find the proportions related to the Z scores. Change to percentiles and compare.
Percentile = precent ≤ a score 
i don't get what you mean. Can you please explain it to me again.

The Z score is the score in terms of standard deviations.
Percentile indicates proportion of scores that are equal to or below a particular score.
Consulting the previously named table should be able to give the percentile for each score for comparison.
If you still don't understand, you need to start a new post indicating the specific problem you are having.