Question

On the 3rd quarter examination in Statistics, the population mean was 70 and the population standard deviation was 9. Determine the standard score of a student who got a score of 88 assuming that the scores are normally distributed.

Answer 1

If $X\sim N(\mu, \sigma^2),$ then $Z=\dfrac{X-\mu}{\sigma}\sim N(0, 1).$

Given $\mu=70, \sigma=9.$

$$Z=\dfrac{88-70}{9}=2$$