Question: Probability (continuous distribution functions)?
suppose the diameter at breast height(in) of trees of a certain type is normally distributed with a=8.8, b=2.8.

a)what is the probability that the diameter of a randomly selected tree will be at least in 10 in? will exceed in 10 ?  Edit

Answer: a)Need to find P(x>=10)=?
z=( x-8.8)/2.8
if x=10 , then z= (10-8.8)/2.8=1.2/2.8=0.43
P(x>=10)=P(z>0.43)=0.5-0.1664=0.3336(Ans.)

  Edit