D4. Cumulative Distributive Functions Flashcards
1
Q
Define Cumulative Distributive Function
A
CDF, a function F(x) = P(X ≤ x) for all x in that support of x.
2
Q
What is the CDF for a uniform distribution over the interval {a,b}?
What do they look like?
A
CDF is a straight line between min and max values.
3
Q
CDFs and PDFs for uniform distributions.
A
Informally a CDF is the area under a PDF.
Uniform: rectangles so calculus is not needed.
4
Q
What is the CDF for a normal distribution?
A
5
Q
Properties for any CDF
A
6
Q
CDFs and PDFs
A
7
Q
How would you find:
- the median value of x
- 1st quartile of x
A
Median: P(X≤x)=0.5 and find x by reversing the equation
1st quartile:
8
Q
How can you find a value if you only have values either side?
A
Linear interpolation.
