posted by Komal .
A normal distribution has a mean of µ = 28 with σ = 5. What is the minimum raw score needed to be in the top 25% of the distribution?
Determine the z-value using a z-table for the top 25%. Substitute the z into the formula, along with the mean and standard deviation. Solve for x.
z = (x - mean)/sd
I hope this will help get you started.