If the variance of a random variable X is 9, what is the standard deviation of X?
9
3
81
6
A committee of 3 people is to be formed from a group of 5. How many different committees are possible?
60
15
20
10
A random variable X follows a uniform distribution between 0 and 10. What is the probability that X is greater than 7?
0.7
0.3
0.1
0.2
What does the addition rule of probability calculate?
Probability of one event AND another event occurring
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
How many different ways can you arrange the letters in the word "DATA"?
4
12
24
16
In a standard deck of 52 cards, you draw one card. What is the probability of drawing a heart or a spade?
1/52
1/4
1/2
1/13
A basketball player makes 80% of her free throws. What is the probability that she makes her first free throw on her third attempt?
0.008
0.032
0.8
0.16
Which of the following is NOT a property of expected value?
E(X + Y) = E(X) + E(Y) for random variables X and Y
E(c) = c for a constant 'c'
E(aX) = aE(X) for a constant 'a'
E(X²) = [E(X)]²
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
0.01
1
What does the Probability Density Function (PDF) represent for a continuous random variable?
The probability of the variable taking on a specific value.
The relative likelihood of the variable falling within a particular range.
A measure of the spread or variability of the variable.
The cumulative probability of the variable up to a given value.