What does the complement rule in probability state?
The probability of two events happening is the sum of their individual probabilities.
The probability of an event not happening is 1 minus the probability of it happening.
The probability of an event happening is equal to the probability of it not happening.
The probability of an event is always 1.
If you roll a fair six-sided die, what is the probability of rolling a 3 OR an even number?
1/2
2/3
1/6
1/3
Which of the following is NOT a valid probability value?
0
1.25
0.75
1
How many different ways can you arrange the letters in the word "DATA"?
4
24
12
16
If a random variable X is multiplied by a constant 'c', how does it affect its expected value?
E(cX) = c * E(X)
E(cX) = E(X) / c
E(cX) = E(X) + c
E(cX) = E(X)
A random variable representing the number of website visitors in an hour is an example of what type of variable?
Continuous
Qualitative
Ordinal
Discrete
For a standard normal distribution (mean 0, standard deviation 1), what does the CDF tell you at the value 0?
The most frequent value in the dataset.
The probability of observing a value of exactly 0.
The probability density at the exact center of the distribution.
The probability of observing a value less than or equal to 0.
If a constant value 'c' is added to every observation of a data set, what happens to the variance?
Increases by 'c'
Remains unchanged
Decreases by 'c'
Increases by 'c²'
A random variable X has a probability distribution as follows: P(X=0) = 0.2, P(X=1) = 0.3, P(X=2) = 0.5. What is the expected value of X?
1.5
0.5
1.2
A basketball player makes 80% of her free throws. What is the probability that she makes her first free throw on her third attempt?
0.16
0.8
0.032
0.008