Practice Flashcards
Flip to reveal answersWhat shape is the normal distribution?
Track your progress — Sign up free to save your progress and get smart review reminders based on spaced repetition.
All 9 Flashcards — The normal curve
Sign up free to track progress and get spaced-repetition review schedules.
Question
What shape is the normal distribution?
Answer
A symmetric bell curve centred on the mean.
Question
For a normal curve, how do the mean, median and mode compare?
Answer
They are all equal (by symmetry).
Question
What is the total area under a normal curve?
Answer
1.
Question
What is P(X < μ) for a normal distribution?
Answer
0.5 — half the area lies below the mean.
Question
How is a probability shown on a normal-curve sketch?
Answer
As the area of the shaded region.
Question
What happens to the curve if the mean increases (σ fixed)?
Answer
It shifts to the right, keeping the same shape.
Question
What happens if σ increases (mean fixed)?
Answer
The curve becomes wider and flatter (more spread).
Question
What does a smaller σ mean for the data?
Answer
The values are more clustered / consistent (taller, narrower curve).
Question
By symmetry, P(X > μ + σ) equals which left-tail probability?
Answer
P(X < μ − σ) — symmetric tails are equal.
Read the notes
Full study notes for The normal curve
Topic 4.9 hub
Normal distribution
More from Topic 4.9
All flashcards in this topic
Math AA SL exam skills
Paper structures & tips
Track your progress with spaced repetition
Sign up free — Aimnova tells you exactly which cards to review and when, so you remember everything before your IB exam.
Start Free