select the correct answer.\nthe scores received by students completing a geology exam are normally…

select the correct answer.\nthe scores received by students completing a geology exam are normally distributed. if the average score is 122 and the standard deviation is 35, what percentage of students scored between 52 and 122?\na. 34.0%\nb. 37.5%\nc. 42.0%\nd. 47.5%\ne. 48.0%
Answer
Explanation:
Step1: Calculate z - scores
The z - score formula is $z=\frac{x - \mu}{\sigma}$, where $x$ is the value, $\mu$ is the mean, and $\sigma$ is the standard deviation. For $x = 52$, $\mu=122$, and $\sigma = 35$, we have $z=\frac{52 - 122}{35}=\frac{-70}{35}=- 2$. The z - score for the mean $x = 122$ is $z=\frac{122 - 122}{35}=0$.
Step2: Use the empirical rule
The empirical rule for a normal distribution states that about 95% of the data lies within $z=-2$ and $z = 2$, and the distribution is symmetric about the mean. The percentage of data between $z=-2$ and $z = 0$ is half of the percentage of data between $z=-2$ and $z = 2$. Since the percentage of data between $z=-2$ and $z = 2$ is 95%, the percentage of data between $z=-2$ and $z = 0$ is $\frac{95%}{2}=47.5%$.
Answer:
D. 47.5%