Why does this work:
Solve[Probability[x <= t, x \[Distributed] NormalDistribution[]] == 0.95 ,t]
But this doesn't:
Solve[Probability[x <= t,x \[Distributed] StudentTDistribution[2.964, 2.071, 5]] ==0.95,t]
How can I solve this problem?
$\begingroup$
$\endgroup$
4
1 Answer
$\begingroup$
$\endgroup$
1
(This may be better as a comment)
This may be an exercise in testing the use of NSolve (which does produce the answer [Version 9]) the normal distribution and StudentTDistribution can be solved with Quantile or InverseCDF, as can be verified by testing solutions.
Quantile[StudentTDistribution[2.964, 2.071, 5], 0.95]
or
InverseCDF[StudentTDistribution[2.964, 2.071, 5], 0.95]
both yielding:
7.13717
-
$\begingroup$ Thank you very much! That helped a lot! $\endgroup$ Commented Nov 22, 2013 at 10:21
Solveis an exact symbolic solver ... it works mostly with linear equations and polynomials and special cases like the Erf function which it knows how to invert. Since your problem is numerical anyway, tryNSolveinstead ofSolve. $\endgroup$FindRootwhenNSolvedoesn't work.FindRootwon't find all roots, just one, but it can handle any "black box" function. $\endgroup$