Question

the distribution of reading scale scores in the 4th grade at truman elementary school was approximately normal with mean $mu = 221$ and standard deviation $sigma = 36$.
educational researchers are conducting an intervention experiment. to participate in the experiment, a student must have a reading scale score in the lower 50% of the scores in their grade level.
what is the maximum reading scale score for students to participate in the intervention experiment?
choose 1 answer:
a 185
b 203

Explanation:

Step1: Recall property of normal distribution

In a normal - distribution, the median (50th percentile) is equal to the mean.

Step2: Identify the required value

Since the students must be in the lower 50% of scores and the mean of a normal distribution divides it into two equal parts, the maximum score for students to participate is the mean of the distribution.

Answer:

Since the mean $\mu = 221$, the maximum reading - scale score for students to participate in the intervention experiment is 221. (Note: There is an error in the provided options as 221 is not among them.)