Expected Value of Probability Distribution Function

Given the probability model below, what is the expected value of the random variable?

• 4.67

• 5

• 14

• 7.5

If the mean number of computers sold per day is 1.7, find the value of j and k.

• j=0.2

  k=0.1

• j=0.1

  k=0.2

• j=0.5

  k=0.5

• I cannot answer this question.

Given that E(X)=2 and E(X^2)=9.Find the variance of X

• 7

• 5

• 77

• 65

P(X=x)= 2x/12 for x=0,1,2,3,4

Find the average value of the calculator sold

• 2/5

• 4/5

• 7/3

• 3/2

Find the mean (expected value) of the probability distribution.

• 85

• 83.2

• 87.1

• 84.4

What E(x) for probability distribution given in the image?

• 2.4

• .103

• -1.03

• 1.03

• Yes, because all of the probabilities are between 0 and 1 inclusive and the sum of all the probabilities is 1.
• No, all probabilities are not be between 0 and 1 inclusive
• No, the sum of all the probabilities is not 1.
• Yes, because the distribution is symmetric

A stockbroker estimates that at the end of the year, there is a 40% chance a stock will be worth $50, a 35% chance it will be worth $60 and a 25% chance it will be worth $70.
What expected value does this broker assign to this stock's end-of-the-year price?

• $58.50

• $60.00

• $62.50

• $65.00

• $2.50

• $5

• -$2.50

• $0

Data was compiled and the number of goals for a hockey team per game and the corresponding probabilities are given below. If this hockey team plays an 82-game season, what is the expected cumulative goal total for the next season?

• 220

• 239

• 261

• 309

• 320