Question 1157874
1. this has .90^12 probability or 0.2824
2. this means 10,11,or 12 trees survive
Can use the calculator or do it by hand for 10 and 11
for 10 it is 12C10^0.9^10*0.1^2=0.2301
for 11 It is 12*.9^11*.1=0.3766
the sum of those three is 0.8891

calculator do 1-binomcdf(12,.9,9), the calculator can only do the left side of the binomial, which isn't what we want.  We find the cumulative probability of 0 to 9 trees and subtract that from 1 to get the probability we want,.