Normal distribution

What you'll learn

1. 1

   Imagine a class of 30 students measuring their heights. Most are around average height, with fewer very short or very tall students.

2. 2

   Here's a normal distribution curve. The highest point is the mean (average). The curve gets lower as you move away from the mean.

3. 3

   What shape does a normal distribution curve look like?

4. 4

   Heights in a class have mean 160 cm and standard deviation 10 cm. What percentage of students are between 150 cm and 170 cm?

5. 5

   Drag the slider to change the standard deviation. Watch how the bell curve changes shape.

6. 6

   In a normal distribution, about what percentage of data lies within 2 standard deviations of the mean?

7. 7

   If exam scores follow a normal distribution with mean 60 and standard deviation 15, what score is 1 standard deviation above the mean?