If you're seeing this message, it means we're having trouble loading external resources on our website.

If you're behind a web filter, please make sure that the domains *.kastatic.org and *.kasandbox.org are unblocked.

Main content

AP®︎/College Statistics

Course: AP®︎/College Statistics > Unit 4

Lesson 5: Normal distribution calculations
Math
AP®︎/College Statistics
Exploring one-variable quantitative data: Percentiles, z-scores, and the normal distribution
Normal distribution calculations
© 2023 Khan AcademyTerms of usePrivacy PolicyCookie Notice

Normal distribution: Area above or below a point

Google Classroom
You might need: Calculator,Z table

Problem

A set of magical wand prices are normally distributed with a mean of 50 dollars and a standard deviation of 4 dollars. A blackthorn wand has a price of 45.20 dollars.
What proportion of wand prices are lower than the price of the blackthorn wand?
You may round your answer to four decimal places.
  • Your answer should be
  • an integer, like 6
  • a simplified proper fraction, like 3/5
  • a simplified improper fraction, like 7/4
  • a mixed number, like 1 3/4
  • an exact decimal, like 0.75
  • a multiple of pi, like 12 pi or 2/3 pi
Stuck?
Stuck?