Random variables Quiz
10 questions · easy to harder · University Statistics · score and step-by-step answers
How it works
- 10 questions, about 30 minutes (a timer counts down; you can hide it). Solve it right here: no sign-up.
- 5 questions have choices. For the others you type the answer: a number like 4, −2, 7/2 or 3.5, or for example x = 4, x = 2 or x = −3, (3, 5), 2x + 1. Use ^ for powers (x^2) and sqrt for √. Any form with the same value counts (7/2 = 3.5).
- One question at a time: Back, Next, Mark for review and the question list at the bottom. A calculator is on the screen.
- At the end: your percent and grade, every question right or wrong, why a wrong choice is wrong, and its step-by-step solution. Then practise the lesson with new questions.
Your answers and results are kept in this browser only, so you can close the page and come back.
1 Question 1
x: 0, 1, 2, 3; P(x): 0.1, 0.3, 0.4, 0.2, find the mean- A) 1.5
- B) 17
- C) 1
- D) 1.7
2 Question 2
x: 1, 2, 3, 4; P(x): 0.4, 0.3, 0.2, 0.1, find the meanType the answer.
3 Question 3
x: 0, 2, 4; P(x): 0.3, 0.4, 0.3, find the expected value- A) 0.2
- B) 1
- C) 20
- D) 2
4 Question 4
x: 1, 2, 3; P(x): 0.5, ?, 0.2, find the missing probabilityType the answer.
5 Question 5
X: 1, 2, 3, 4, 5; P(x): 0.1, 0.2, 0.3, 0.3, 0.1, find the expected value- A) 1
- B) 31
- C) 3
- D) 3.1
6 Question 6
x: 0, 1, 2, 3; P(x): 0.25, 0.25, 0.25, ?, find the missing probabilityType the answer.
7 Question 7
x: 0, 1, 2, 3; P(x): 0.1, 0.3, 0.4, 0.2, find the standard deviation- A) 0.9
- B) 0.09
- C) 1.7
- D) 0.81
8 Question 8
X: 0, 1, 2, 3, 4; P(x): 0.1, 0.2, 0.4, 0.2, 0.1, find the standard deviationType the answer.
9 Question 9
x: 0, 1, 2, 3; P(x): 0.4, 0.3, 0.2, 0.1, find the standard deviation- A) 1
- B) 0.1
- C) 10
10 Question 10
x: 0, 1, 2, 3, 4; P(x): 0.05, 0.15, 0.4, 0.3, 0.1, find the meanType the answer.