This preview shows page 1. Sign up to view the full content.
Unformatted text preview: the curve
f(X) by the area P (a ≤ X ≤ b) a b X Probability as
Area Under the Curve
The total area under the curve is 1.0 or 100%, and
the curve is symmetric, so 50% is above the mean,
50% is below
f(X) 0.5 0.5 μ P(−∞ < X < ∞ ) = 1.0 X General Procedure for
To find P(a < X < b) when X is
Step 1: Draw the normal curve for the problem in
terms of X
Step 2: Translate X-values to Z-values
Step 3: Use the Standardized Normal Table Solving for Probabilities
Suppose X is normal with mean 8.0 and
standard deviation 5.0
Find the probability that someone will
score above 8.6.
score X 8.0
8.6 Finding the Raw Score for a
Steps to find the raw score or X value
for a known probability:
1. Find the Z value for the known
2. Convert to X units using the formula: X = μ + Zσ...
View Full Document
This document was uploaded on 02/19/2014.
- Spring '14