Quick lookup of cdf and quantile for t-distribution.

k <- 27  # degrees of freedom
p <- 0.95
q <- qt(p,df=k) # quantile of t-distribution

t-distribution with 27 degrees of freedom
quantile (0.95) = 1.7032884

x <- 1.703
p <- pt(x,df=k)  # cdf of t-distribution

cdf (1.703) = 0.9499727