A coffee shop owner knows from past records that 20 of all c

A coffee shop owner knows from past records that 20% of all customers who enter her store will buy a danish. if 10 people enter the store what is the probability that fewer than 5 do not buy a danish?

Solution

Prob for any customer buying a danish = 0.20

No of people entering n = 10

X - no of people buying danish is binomial with n =10, p = 0.20

the probability that fewer than 5 do not buy a danish

= P(X\'<5) = P(X>5)

=0.006369