Week 6: discrete probability mass function, continuous probability density function, notation, concept

What is the discrete probability mass function?

What is the continuous probability density function?

The expected value is found using integration, but it’s easier to do w x h to find the area!

What is the expected value (mean) and variance for a probability density function?

What is the normal probability density function?

Referred to as gaussian distribution or bell curve

What does the the expected value and variance mean in a bell curve?

What is the 68/95/99.7 rule? (empirical rule)

For any normal model:

• 68% of the probability is between ± 1 of it’s expected value

• 95% of probability is between ± 2 of its expected value

• 99.7% of probability is between ± 3 of its expected value

What is the a z-score?

A z-score gives the number of standard deivations that a value x, is above or below the mean!

• - z score → lower than mean (left)

• + z score → higher than mean (right)