ST3: The normal distribution

Question 1

What is Normal or “Gaussian” distribution?

Answer 1

It is symmetrical “bell shaped curve”.

Question 2

What tells standard deviation about curve of normal distribution?

Answer 2

It tells Width of the curve.

Question 3

Why knowing standard deviation is helpful?

Answer 3

It is helpful to know standard deviation because normal curves are drawn such that 95% of the measurements fall between +/- 2 standard deviations around the mean.

Question 4

What do you need to know to draw normal distribution?

Answer 4

1. The average measurement (mean), this telles where the center of the curve goes.
2. The sdandard deviation of the measurements, this tells how wide the curve should be. (wider>shorter, narrower>taller).