Download 23A Discrete Random Variables

Name: _______________________
Class: __________
Date:_____________
Math SL: 23A Discrete Random
Variables (RV)
Calculator Review:
1. Find the coefficient of x5 in the expansion of (3x – 2)8.
2. Solve the equation 3 sin2 x = cos2 x, for 0°  x  180°.
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23A Discrete Random Variables
Today’s Objectives:
(1) to understand discrete random variables
Random Variables
A random variable represents the possible outcomes that result from some chance event. A
random variable usually equals a number or a range of numbers. Random variables are
represented by capital letters. Use lower case values for actual measured values of the random
variable.
Notation examples:
P( X = x)
P ( a < Y £ b)
A _________________ random variable X has a finite or countable number of possible values.
For example: M = the number of mobile telephones that you own, B = the number of bicycles that
each family has. In general to determine the value of a discrete random variable we need to
______________.
A _____________________________ random variable X could take on an infinite number of values in
some interval.
For example: H = the heights of students in different classes, V = the volume of Coca Cola
consumed during each month of the year. In general to determine the value of a continuous
random variable we need to __________________.
IB example of Discrete Random Variable (In 2013 36331 students took MATH SL)
X=Math SL Grade
P( X = x)
1
2
3
4
5
6
7
1.4%
10.1%
17.6%
19.3%
23.8%
19.1%
8.7%
Determine:
1. P ( X = 6 or X = 7 )
2. P ( 4 £ X < 7 )
3. P ( X < 7 or X > 3)
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In groups, provide your own example of a discrete random variable. Be sure to include all
possible outcomes and their respective probabilities.
Hmwk#50
23A Discrete random variables pg. 631 # 2 – 4
Note: I would strongly recommend that you start to review for the next test. If you have
any questions regarding topics/concepts, be proactive and seek help. If you feel you need
more practice, then be proactive and COMPLETE more problems.
Continue researching a math exploration topic – find math involved.
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