What's the probability that exactly 5 out of the next 8 customers will buy cake pops? (Hint: remember to show the setup!)

Question

Lindsay knows 48% of people who walk into her dessert show will buy cake pops.

Answer 1

this is a binomial distribution, with chance of success (probability someone will buy a cake pop) of p=0.48, and chance of failure (probability someone will NOT buy a cake pop) of q=0.52. remember / realize that p + q =1 in every binomial distribution problem because p and q are the only two possible outcomes.

the form of a binomial probability is _nC_r (p)^r (q)^n-r . r is the number of successes and n is the number of trials. _nC_r is n! / [r! (n-r)!]

in this case, your solution comes from

₈C₅ (0.48)⁵ (0.52)^8-5

= {8! / [5! (8-5)!]} * (0.48)⁵ (0.52)³

= {(8*7*6*5*4*3*2*1) / [(5*4*3*2*1)*(3*2*1)]} * (0.48)⁵ (0.52)³

= 0.2006