Question 1194500
at most 2 includes 0, 1, and 2
p(0)=15C0*0.8^15=0.0352
p(1)=15C1*0.2^1*0.8^14=0.1319
p(2)=15C2*0.2^2*0.8^13=0.2309
that total is 0.3980
Also binomcdf(15,0.2,2)
-at least 5 can do with 1-bionomcdf(15,0.2,4)=0.1642
OR do p(3)=15C3*0.2^3*0.8^12 and p(4)=15C4*0.2^4*0.8^11, sum those to the three above and subtract from 1.