Question

Let x be the normal distribution with μ=52.1 and σ=7.5. What is the x-value representing the twelfth percentile, P12. (Round to the nearest hundredth.):

Answer 1

In the standard normal distribution, we have roughly

`P(Z\le-1.1750)\approx0.12`

so the corresponding
`x` value for the 12th percentile is

`-1.1750\approx(x-52.1)/(7.5)\implies x\approx43.3`