Probability & Statistics / Data & Inference
What is the probability of rolling an even number on a 6-sided die?
3/6 = 1/2
Name two ways to collect data in a study.
Survey, experiment (also: simulation, census, observational study)
What is the mean of: 2, 4, 6, 8, 10?
6
What is a common source of bias in data collection?
Voluntary response bias
Define “independent events” in probability
Events where the outcome of one does not affect the other
What does a confidence interval tell us?
The range of values likely to contain the true population parameter
In a normal distribution, what % lies within 2 standard deviations?
About 95%
If a margin of error is ±3% and the result is 48%, what is the confidence interval?
45% to 51%
Describe a situation that would introduce bias in a survey
Leading questions, non-random sampling, or voluntary response bias
How do you know if a result is statistically significant?
If it lies far in the tails (outside expected range), not likely due to chance