Binomials

Question 1

Define random variable

Answer 1

• A numerical variable whose value depends on chance
• Ex., randomly selecting student height

Question 2

State the criteria of a binomial random variable

Answer 2

1. Fixed number of observations/trials (n)
2. Trials are independent
3. Outcome of each trial can be classified into 2 categories (success of failure)
4. The probability of success (p) and failure (q) is constant across trials

Question 3

What is a binomial distribution?

Answer 3

• This includes all possible values of a binomial random variable and their assigned probabilities

Question 4

State the formula for calculating mean and SD of a binomial

Answer 4

Mean μ = np

Standard deviation 𝜎 = √npq

• Variance = 𝜎²

Question 5

Explain what each gives you:

1. dbinom
2. pbinom
3. qbinom

Answer 5

1.