3.89 FAQ-327 How to compute the critical value of t distribution?

Last Update: 2/4/2015

Critical-Value-of-t-Dist

Use tinv(t, df) in the command window, for example, type tinv(0.05,15)= in the command window

In addition, Origin also support critical value of other distributions

Distribution	Labtalk Function
Normal distribution	norminv(p)
F distribution	finv(p, df1, df2)
Beta distribution	betainv(p, alpha, beta)
Chi Square distribution	chi2inv(p,df)
Gamma distribution	gaminv(p, a, b)
Weibull distribution	wblinv(p, a, b)

Notes: The functions return the critical value for lower tailed probability. A two-tailed-value can be returned by replacing probablity with (1-probability/2)