Cumulative Distribution

Question

If the cumulative distribution function of X is given below, then find P (X < 0.80).

 f(x)=0, if x ≤ 0 

f(x)=x^2, if 0 < x ≤ 1 

f(x)=1, if x > 1

Answer 1

Since the cdf is a smooth function for 0 < X < 1,

 

P( X < .8)  is just cdf(.8)  =   .64