Given mean, standard deviation, sample size, find number of

On a standardized placement test given at a large university, scores are normally distributed with mean nof 1000 and standard deviation of 250. There are 20,000 students in the sample.

1. How many students score higher than 1200?

2. How many students score between 700 and 1250?

Give us a clue, please. I'll give you a hint.

\(\displaystyle \L\;\frac{x-\mu}{\sigma}\)