Respuesta :
Answer: 0.75
Explanation:
Mean(μ) = 300
Standard deviation(σ) = 20
Find the z-score of a person who scored 315 on the exam ;
Raw score (x) = 315
Z = (raw score - mean) ÷ standard deviation
Z = (x - μ) ÷ σ
Z = (315 - 300) ÷ 20
Z = 15 ÷ 20
Z = 0.75
Answer:
3
Explanation:
[tex]z=\frac{x-μ}{σ}[/tex]
[tex]z=\frac{360-300}{20}[/tex]
[tex]z=\frac{60}{20}[/tex]
[tex]z=3[/tex]
They scored 3 standard deviations above the mean
(Which is better than 99.9% of test takers)