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?

Answer 1

Use z-scores.

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.

Formula:
z = (x - mean)/sd

I hope this will help get you started.