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Statistics and probability

Course: Statistics and probability > Unit 9

Lesson 1: Discrete random variables
Math
Statistics and probability
Random variables
Discrete random variables
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Expected value

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Problem

X is a discrete random variable. The graph below defines a probability distribution for X.
What is the expected value of X?
  • Your answer should be
  • an integer, like 6
  • a simplified proper fraction, like 3/5
  • a simplified improper fraction, like 7/4
  • a mixed number, like 1 3/4
  • an exact decimal, like 0.75
  • a multiple of pi, like 12 pi or 2/3 pi
A bar graph shows the vertical axis labeled P of capital x equals x and the horizontal axis is labeled x. The bar lines shows the following: 0 bar line extends to 35 hundredths. 10 bar line extends to 25 hundredths. The 20 bar line extends to 4 tenths.
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