Answer: The required z-score = 1.25
Step-by-step explanation:
Let x be a random variable that denotes the scores in the exam.
The formula for z-score = [tex]\dfrac{X-\text{mean}}{\text{standard deviation}}[/tex]
As per given, we have
X= 625, mean=500, standard deviation = 100
Z-score = [tex]\dfrac{625-500}{100}[/tex]
i.e. Z-score = [tex]\dfrac{125}{100}[/tex]
i.e. Z-score =1.25
Hence, the required z-score = 1.25
