In matlab there is a inbuilt function chi2inv(P,V)

P-probability of confidence interval.

V- degree of freedom.

My data range is with [0.004 0.5] and determined value for V= 44.

if we pass these values in above matlab function , it gives value around 64 as threshold, but for my data , the threshold should be within the data range [0.004 0.5].

My question is how to adapt the data to chi square distribution?