Sangeetha Pulapaka

Consider the normal distribution with mean μ=221 and standard deviation σ=36.

We want to find the reading scale score such that the area under the curve to its left is 0.5.

We can use the standard normal probabilities table to determine the z-score we are looking for.

So we have a z-score of 0 from the table.

We know that

z = \frac{x - \mu}{\sigma}

Plugging in the known values and solving for x we get

0 = \frac{x-221}{36}

x = 221

So, the maximum reading scale score for students to participate in the intervention experiment is 221.