Offline CDF(Cumulative Density Function) Calculator

While CDF tables are readily available in textbooks and online, they typically only provide probabilities for a limited set of pre-defined values (often corresponding to common alpha levels). Calculating the CDF for an arbitrary X or F value, especially when offline, can be challenging. Having an Android app that can calculate CDFs offline would be very beneficial for several reasons:

Below  are definitions of selected distribution CDF calculation formula based on the above app.

CDF(n, σ) n for normal distribution, σ is sigma or z value(positive only is meaningful for double tail P value calculation).
CDF(n, a,b) n for normal distribution, a for lower limit, b for upper limit for single tail hypothesis test.
CDF(t, x,ν) t for student t distribution, x is t value calculated from data, ν is degree of freedom.
CDF(X2,x,k) X2 for χ² distribution, x is χ² critical value calculated from data, k is degree of freedom.
CDF(F,f,n1,n2) F for F distribution, f is F or F critical value from data , n1 and n2 are degree of freedom.

Below is the results for selected parameters.