Continuous Probability Distributions
Chapter 6
Uniform Probability Normal Probability
Distribution Distribution
Continuous probability distribution 4 ▪ “Bell”-shaped.
probability that random variable
▪ Symmetrical around mean.
assume value in any interval = same 4
▪ Total area under curve = 1.
each interval of equal length.
The probability density function f(x)
does NOT directly provide
probabilities.
f(x)≥0 for all -∞ < x < ∞
Area under probability density
function f(x) 4 values of -∞ < x < ∞
equals one.
Continuous probability distribution -
probability density function = bell
shaped & determined by mean (μ) &
standard deviation (σ).
Highest point = mean, median & mode.
Standard deviation determines how
flat/wide curve is. Larger values of =
wider, flatter curves, showing more
variability in data.
Chapter 6
Uniform Probability Normal Probability
Distribution Distribution
Continuous probability distribution 4 ▪ “Bell”-shaped.
probability that random variable
▪ Symmetrical around mean.
assume value in any interval = same 4
▪ Total area under curve = 1.
each interval of equal length.
The probability density function f(x)
does NOT directly provide
probabilities.
f(x)≥0 for all -∞ < x < ∞
Area under probability density
function f(x) 4 values of -∞ < x < ∞
equals one.
Continuous probability distribution -
probability density function = bell
shaped & determined by mean (μ) &
standard deviation (σ).
Highest point = mean, median & mode.
Standard deviation determines how
flat/wide curve is. Larger values of =
wider, flatter curves, showing more
variability in data.
