Question

A population of values has a normal distribution with μ You intend to draw a random sample of size n 168 197.8 and σ 82.6. Find P39, which is the mean separating the bottom 39% means from the top 61% means. P39 (for sample means)-( 174.7 Enter your answers as numbers accurate to 1 decimal place. Answers obtained using exact z-scores or z-scores rounded to 3 decimal places are accepted. License Points possible: 1 Unlimited attempts. Score on last attempt: 0. Score in gradebook: 0

Answer 1

Here we need z-score that has 0.39 area to its left. Using excel function, "=NORMSINV(0.39)" the z-score -0.28 has 0.39 area to its left. So required percentile is

$z=rac{P_{39}-mu}{sigma/sqrt{n}}$