Probability Density Functions

Question 1

For continuous random variables, what is the probability of a specific point

Answer 1

0, you measure over a range not at a specific point

Question 2

What does the Probability Density Function (PDF) represent

Answer 2

Density, not actual probility

Question 3

How do you calculate a probability

Answer 3

Integrate the PDF over an interval e.g. -1 to 1

Question 4

What is the Cumulative distribution function

Answer 4

F(x) = P(X <=x)

Probability that X is smaller than a set value

So the CDF is just the PDF from -infinity to a certain value. The cumulative probability up to a certain value

Question 5

What are the 2 properties of the PDF

Answer 5

The values can’t be negative
The total area under the curve must be equal to 1

Question 6

How do you calculate the probability between b and a

Answer 6

F(b) - F(a)