CCSS HSS-MD.A.2 Worksheets
Grade 12 · Using Probability to Make Decisions
Calculate the expected value of a random variable and interpret it as the mean of the probability distribution, and find its variance and standard deviation.
Below are free printable worksheets that support HSS-MD.A.2. Print them as PDFs, or generate a fresh one. Every math answer key is computed in code, so it is never wrong.
Teaching guide
What students learn
Calculate the expected value of a random variable and interpret it as the mean of the probability distribution, and find its variance and standard deviation.
Worked example
A discrete random variable X has this probability distribution: P(X=0)=0.2, P(X=3)=0.2, P(X=4)=0.1, P(X=6)=0.2, P(X=9)=0.3. Find the expected value E(X).
Answer: 4.9
Why: E(X) = sum of x*P(X=x) = 0(0.2) + 3(0.2) + 4(0.1) + 6(0.2) + 9(0.3) = 4.9
Generated and checked in code, so it is correct.