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)?
0.75
0.25
1.00
0.50
What is the probability that a randomly selected person was born on a Tuesday, assuming births are equally likely on any day of the week?
1/52
1/365
1/7
1/12
Which of the following measures the spread or dispersion of a random variable's values around its expected value?
Expected Value
Probability Mass Function
Variance
Cumulative Distribution Function
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?
(1/6)^3 * (5/6)
(5/6)^4 * (1/6)
(5/6)^3 * (1/6)
(1/6)^4
A random variable Z has a standard deviation of 2. What is the variance of 3Z?
6
18
12
36
A committee of 3 people is to be formed from a group of 5. How many different committees are possible?
20
60
15
10
What is the value of 5! (5 factorial)?
120
25
If a random variable X is multiplied by a constant 'c', how does it affect its expected value?
E(cX) = E(X)
E(cX) = c * E(X)
E(cX) = E(X) / c
E(cX) = E(X) + c
What does the addition rule of probability calculate?
Probability of two events occurring given that one has already happened
Probability of one event OR another event occurring
Probability of an event NOT occurring
Probability of one event AND another event occurring
A fair six-sided die is rolled. What is the expected value of the roll?
4
3.5
3
2.5