# find scale and shape parameter of Weibull distribution by having the 50 and 90 percent quantiles

I have the 50 and 90 percent quantile of a Weibull distribution. Is it possible to get the shape and scale parameter just with this information?

Mathematically I have this formula for calculating the Weibull quantiles :

q(p,k,A) = A(-ln(1-p))^(1/k)


then I have the q value for p = 0.5 and 0.9 :

q50 = A(-ln(1-0.5))^(1/k)
q90 = A(-ln(1-0.9))^(1/k)


A and k parameter that I could get from this set of equations would be the correct and unique answer?

• What are your thoughts about that? What have you tried so far? – Taroccoesbrocco Sep 19 '18 at 14:23