A random variable Y has an expected value of 5 and a variance of 4. What is the expected value of Y - 2?
1
7
9
3
A fair six-sided die is rolled. What is the probability of rolling an even number?
1/2
1/3
2/3
1/6
If the variance of a random variable X is 9, what is the standard deviation of X?
81
6
If a random variable X represents the number of tails in two coin flips, what is P(X = 1) using its Probability Mass Function (PMF)?
0.25
0.75
0.50
1.00
A fair coin is flipped twice. What is the expected value of the number of heads?
0
1.5
2
In a standard deck of 52 cards, you draw one card. What is the probability of drawing a heart or a spade?
1/4
1/52
1/13
If a constant value 'c' is added to every observation of a data set, what happens to the variance?
Increases by 'c²'
Decreases by 'c'
Remains unchanged
Increases by 'c'
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
What is the variance of a standard normal distribution (mean = 0, standard deviation = 1)?
0.5
In a lottery, 1000 tickets are sold and there is one winning ticket. If you buy one ticket, what is the probability of winning?
0.001
0.1
0.01