Question

A college-entrance exam is designed so that scores are normally distributed with a mean of 500 and a standard deviation of 100. You scored a 625. Calculate your z-score to the nearest hundredth (i.e. 2 decimal places).
z=

Answer 1

Answer: 1.25

Step-by-step explanation:

Given: A college-entrance exam is designed so that scores are normally distributed with a mean$(\mu)$ = 500 and a standard deviation$(\sigma)$ =  100.

A z-score measures how many standard deviations a given measurement deviates from the mean.

Let Y be a random variable that denotes the scores in the exam.

Formula for z-score = $\dfrac{Y-\mu}{\sigma}$

Z-score = $\dfrac{625-500}{100}$

⇒ Z-score = $\dfrac{125}{100}$

⇒Z-score =1.25

Therefore , the required z-score = 1.25