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Density function

  • Thread starter apiwowar
  • Start date
  • #1
96
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p(t) = Ce-Ct

i know P(t) is the fraction of the group surviving t years or less

now the question is: suppose a patient has a 70% probability of surviving at least 2 years, find C.

to find c i would take the integral of p(t) but what would my limits be? surviving 2 at least 2 years, so thats more than 2 years. would i have my lower limit be 2 and then have my upper limit be infiniti or just a big number?

any help would be appreciated
 

Answers and Replies

  • #2
236
0
Not my field, but compute [tex]\int_0^xCe^{-Ct}dt[/tex]. What's the limit as x goes to infinity? Does it depend on C?

I think you want to find C so that the integral from 0 to 2 years equals 70% of the integral from 0 to infinity.
 

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