How big a sample? 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
Sample size: 95% confidence, sd 15, error bound 2- A) n = 217
- B) n = 216
- C) n = 0.9750
- D) n = 216.09
2 Question 2
Sample size: 90% confidence, sd 10, error bound 2Type the answer.
3 Question 3
Sample size: 99% confidence, sd 12, error bound 3- A) n = 0.9950
- B) n = 107
- C) n = 106
- D) n = 1070
4 Question 4
Sample size: 90% confidence, sd 5, error bound 1Type the answer.
5 Question 5
Sample size: 95% confidence, sd 6, error bound 1.5- A) n = 620
- B) n = 62
- C) n = 0.9750
- D) n = 61
6 Question 6
Sample size for a proportion: 90% confidence, error bound 0.03Type the answer.
7 Question 7
Sample size for a proportion: 95% confidence, error bound 0.04, p′ = 0.2- A) n = 384
- B) n = 385
- C) n = 0.8
- D) n = 0.9750
8 Question 8
Sample size: 95% confidence, sd 2.5, error bound 0.5Type the answer.
9 Question 9
Sample size for a proportion: 99% confidence, error bound 0.04- A) n = 1036
- B) n = 0.5
- C) n = 0.9950
- D) n = 1037
10 Question 10
Sample size for a proportion: 95% confidence, error bound 0.02Type the answer.