Random variables and probability models

STA 112. Practice questions, not past papers.

Lessons

• Map outcomes to numbers
• Discrete and continuous models

Practice questions

1. A random variable is best defined as what?

   Statistics study edition practice item Q078; Source: T48-51, S12, S15

2. For a continuous variable with a density, P(X=c) equals what?

   Statistics study edition practice item Q079; Source: T48-51, S12, S15

3. Which condition must a probability mass function satisfy?

   Statistics study edition practice item Q080; Source: T48-51, S12, S15

4. Why are two-dice sums not equally likely?

   Statistics study edition practice item Q081; Source: T48-51, S12, S15

5. A fair coin is tossed independently 2 times. What is the probability of at least one head? Give the value to 4 decimal places.

   Statistics study edition practice item Q082; Source: T49-51

6. A fair coin is tossed independently 3 times. What is the probability of at least one head? Give the value to 4 decimal places.

   Statistics study edition practice item Q083; Source: T49-51

7. A fair coin is tossed independently 4 times. What is the probability of at least one head? Give the value to 4 decimal places.

   Statistics study edition practice item Q084; Source: T49-51

8. The support of X is the set of its possible _____.

   Statistics study edition practice item F028; Source: T48-51, S12, S15

9. For a continuous density model, P(X=c) is _____.

   Statistics study edition practice item F029; Source: T48-51, S12, S15

Topic gap report