A random variable Y has an expected value of 5 and a variance of 4. What is the expected value of Y - 2?
7
9
3
1
What does the addition rule of probability calculate?
Probability of one event AND another event occurring
Probability of one event OR another event occurring
Probability of an event NOT occurring
Probability of two events occurring given that one has already happened
If a random variable X follows a standard normal distribution, what is P(X = 0)?
0
Cannot be determined.
0.5
Suppose you are playing a game where you flip a coin until you get heads. What is the probability that it takes exactly 4 flips to get the first heads?
1/2
1/16
1/4
1/8
A random variable Z has a standard deviation of 2. What is the variance of 3Z?
12
36
18
6
Which of the following measures the spread or dispersion of a random variable's values around its expected value?
Cumulative Distribution Function
Expected Value
Probability Mass Function
Variance
A fair six-sided die is rolled. What is the expected value of the roll?
4
3.5
2.5
You are playing a game where you roll a die until you get a 6. What is the probability that you will roll the die exactly 4 times before winning?
(5/6)^3 * (1/6)
(1/6)^4
(5/6)^4 * (1/6)
(1/6)^3 * (5/6)
A basketball player makes 80% of his free throws. What is the probability that he makes his next two free throws?
0.64
0.96
0.40
0.80
If a constant value 'c' is added to every observation of a data set, what happens to the variance?
Remains unchanged
Increases by 'c²'
Increases by 'c'
Decreases by 'c'