Subjects › Probability & Statistics
Distributions
Normal and binomial distributions, and what a standard deviation buys you.
The idea
The empirical rule (68-95-99.7) is worth memorising because it converts a standard deviation from an abstraction into a statement about how unusual something is.
Lesson
No lesson built yet. The worked solutions below are the material it would be assembled from.
Questions (3)
| Question | Type | Difficulty | Drift | Accuracy |
|---|---|---|---|---|
| Scores are normally distributed with mean 100 and standard deviation 15. Approximately what percentage of scor… | numeric | Moderate 0.10 | — | — (0) |
| With mean 100 and standard deviation 15, what is the z-score of a value of 130? | numeric | Hard 0.70 | — | — (0) |
| A fair coin is tossed 10 times. Which is more likely: exactly 5 heads, or between 4 and 6 heads inclusive? | mcq | Hard 1.30 | — | — (0) |