Question 1161870
This is the probability that given a fail rate of 0.15, at most 1 (0, 1) will occur when 26 are sampled
Also on calculator 2nd VARS binomialcdf  ENTER (26,0.15,1) for 0.0817

for 0 the probability is 0.85^26=0.0146
for 1 the probability is 26C1*0.85^25*0.15=0.0671
That sum is 0.0817