bttang -

Assuming df = 19, and displaying 6 significant digits,

1) P(T1) = TDIST(1,19,1) = 0.164938

2a) P(T<-0.1) = TDIST(ABS(-0.1),19,1) = 0.460696

2b) P(T<-0.1 or T1) = P(T<-0.1) + P(T1) = 0.625634

2c) P(T<-1 or T1) = TDIST(1,19,2) = 0.329877

3) t* such that P(Tt*) = .05, t* = TINV(2*0.05,19) = 1.729133

- Mike
http://www.mikemiddleton.com

wrote in message
oups.com...
If I randomly draw 20 subjects from a population, and I want to use the
TDIST and TINV how do i calculate

1) Pr[T1.0]

2) Pr[T<-0.1 or T1.0]

t* such that Pr[Tt*]= .05