Types of Random Variables

Mean of a Discrete Random Variable

Multiple Choice

• expected value of X

  
  

• average of X

• variance of X

• standard deviation of X

Multiple Choice

• E(x)

• e(x)

• E(X)

• e(X)

Multiple Choice

What is the expected value when a fair six-sided die is tossed?

Express your answer as a fraction in lowest terms, such as 2/7 or 4/3.

• 1/6
• 7/2
• 3/4
• 5/2

Fill in the Blanks

Multiple Choice

Rommel works for an Internet cafe, where he earns ₱50 per hour. The number of hours he works each week varies between 20 and 40 hours, depending on how busy the cafe is during the week. Over the past year, he has compiled the following probability distribution which describes the probability of getting 20, 25, 30, 35, or 40 hours in any random week. If Rommel wants to move to a new house and knows that he should not spend more than a third of his average income on housing, how much can he afford for rent?

• ₱480.83

• ₱567.50

• ₱1442.50

• ₱307.65