• Support PF! Buy your school textbooks, materials and every day products Here!

Standard Gamma Distribution

  • Thread starter kdizzle711
  • Start date
  • #1
27
0

Homework Statement


This is an example in my book with omitted steps. Suppose the reaction time X of a randomnly selected individual to a certain stimulus has a standard gamma distribution with alpha=2. When X is continuous

P(2<=X<=5) = F(5;2)-F(3;2) = .960-.801 = .159




Homework Equations



F(x;alpha) = integral from x to 0 [(y^(alpha-1))*(e^-y)]/(gamma(alpha)


The Attempt at a Solution



I have followed the equation and placed 5 for y and 2 for alpha but the numbers are not matching up. In the test it says that gamma(alpha) is equal to one. Please help I have a test tommorow. Thanks
 

Answers and Replies

  • #2
430
3
What exactly is the problem? What numbers are you expecting and what numbers are you getting?

You write:
P(2 <= X <= 5) = .159
but is this what you're supposed to get, or what you're actually getting?

I get P(2 <= X <=5)=.159 as well using the exact formulas you posted (minor nitpick: the integral is from 0 to x, not from x to 0, but I assume this was just a typo).
 

Related Threads for: Standard Gamma Distribution

  • Last Post
Replies
1
Views
3K
  • Last Post
Replies
7
Views
9K
  • Last Post
Replies
11
Views
652
  • Last Post
Replies
1
Views
1K
  • Last Post
Replies
6
Views
2K
  • Last Post
Replies
6
Views
2K
  • Last Post
Replies
2
Views
1K
Replies
0
Views
1K
Top