Random Variable

The probability of winning is 1/3.  Bob plays 6 games. Find P(win exactly 5 games):

• .6803

• .0178

• .0164

• .9986

Given the probability model in the table below, what is the expected value of the random variable?
  X        50          20        5
P(X)     0.1         0.3      0.6

• 14

• 4.67

• 5

• 7.5

If X~B(9,0.2), find P(X=5).

• 0.0016

• 0.0165

• 0.1065

• 0.5016

When rolling a fair die 100 times, what is the probability of rolling a "4"exactly 25 times?

• 0.010

• 0.167

• 0.25

• 0.021

If you were to flip a coin 20 times, what is the probability you would get exactly 10 heads?

• 50%

• 17.62%

• .58.81%

• 41.19%

counts the number of trials needed to obtain the 1st success. X = 1,2,3,…

• Geometric

• Binomial

• Both

• Neither

Which of the following random variables is NOT continuous?

• Amount of gasoline in a car.

• Time it takes to commute to work.

• Number of goals scored by a hockey team.

• Lifetime of a AAA battery.

Which of the following variables can assume only a finite number of values and can be determined by simply counting?

• Continuous Random Variable

• Discrete Random Variable

• Discrete Probability Distribution

• Pay Off Value

Which of the following is a discrete random variable?

• The height of the building.

• The time to finish answering a test.

• The number of times you visit the social media in a day.

• The weight of the students.

Which of the following statements is true?

• A random variable is a quantity having a numerical value for each member of a group, especially one whose values occur according to a frequency distribution.

• A random variable is a quantity having a value for each member of a group, especially one whose values occur according to a frequency distribution.

• A random variable is a quality having a numerical value for each member of a group, especially one whose values occur according to a frequency distribution.