Download Module 16: Probability Distributions Random Variable, x: A random

Module 16: Probability Distributions
Random Variable, x:
A random Variable is ___________________________________ if it represents counted data.
A random variable is_____________________________________ if it represents measured data.
Determine whether the random variable x is discrete or continuous.
1. x represents the volume of blood drawn for a
2. x represents the attendance at the national
blood test.
statistics conference.
3. x represents the distance a football travels
after being kicked.
4. x represents the number of hurricanes that hit
the United States in 2012.
A discrete probability distribution:


The probability of each value is between 0 and 1.
The sum of all probabilities is 1.
Determine whether the distribution is a probability distribution.
5.
6.
X P(x)
X
7 0.28
1
8 0.21
2
10 0.43
3
13 0.08
4
P(x)
0.34
1.21
0.02
0.21
Expected Mean:
We can measure the center of a probability distribution with its mean and standard
deviation. Calculate the Mean and Standard Deviation of the following distribution
with your graphing calculator!
7.
8.
Cats Households
P(x)
Number of
Math Classes HS Seniors
P(x)
0
1262
Taken In HS
1
832
0
0
2
423
1
72
3
96
2
212
4
23
3
725
5
12
4
546
5
213
6
32
Σ
.
Σ
.
Σ
.
Calculate the Mean (expected value):
Calculate the Mean (expected value):
Calculate the Standard Deviation:
Calculate the Standard Deviation:
Interpretation:
Interpretation:
Σ
.