Question 1074651
At least 12 includes 12,13,14,15
for 12
15C12.85^12*.15^3=0.2184
15C13.85^13*.15^2=0.2856
15C14^.85^14*.15=0.2312
15C15.85^15=0.0874
Sum is 0.8226
probability at least 12 attend is 0.823.