Probability Review

Front

What is the expected value in probability?

Back

The expected value is the average of all possible outcomes of a random variable, weighted by their probabilities.

Front

How do you calculate the expected value of a discrete random variable?

Back

Multiply each possible outcome by its probability and sum all these products.

Front

What is the formula for combinations?

Back

C(n, r) = n! / (r!(n - r)!) where n is the total number of items, and r is the number of items to choose.

Front

What is the difference between permutations and combinations?

Back

Permutations consider the order of selection, while combinations do not.

Front

How many ways can you arrange 4 letters from the word 'RHOMBUS'?

Back

840 ways.

Front

If a bag contains 10 balls numbered 3 through 12, what is the expected value of a draw?

Back

7.5.

Front

What is the total number of outfits possible with 5 pairs of jeans, 8 t-shirts, and 2 pairs of shoes?

Back

80 outfits.

Front

What is the expected number of cars in an American household?

Back

1.75 cars.

Front

How do you find the total number of arrangements of a set of items?

Back

Use the factorial of the number of items, n!, to find the total arrangements.

Front

What is a random variable?

Back

A random variable is a variable whose possible values are numerical outcomes of a random phenomenon.