Can you please help me to solve question d? A cereal company puts a Star Wars to
ID: 3131241 • Letter: C
Question
Can you please help me to solve question d?
A cereal company puts a Star Wars toy in each of its boxes as a sales promotion. Twenty percent of the cereal boxes contain a toy with featuring Kylo Ren. You are a huge Kylo Ren fan, so you really want one of these toys. You decide to buy 100 boxes of cereal from the warehouse store to be on the safe side. What is the probability that you do not get any Kylo Ren toys? Identify the distribution you are using. What is the expected number of Kylo Ren toys that you will find in 100 boxes? If each box of cereal costs $3.50, and you believe the value of the Kylo Ren toy will be approximately $50 in a few years, are you doing a smart thing by purchasing 100 boxes? (Think about expected value for the cost and the profit.) How many boxes of cereal would you need to buy to be at least 95% sure of finding at least 1 Kylo Ren toy?Explanation / Answer
Prob of success = Getting a toy = 0.20
q = failure = 0.8
Two outcomes and each trial is independent.
Hence X no of toys is binomial with p =0.20
Let n boxes be purchased
P(X>=1) = 1-P(X=0)
= 1-qn >=0.95
Or 0.8n <= 1-0.95 = 0.05
n ln 0.8 <= ln 0.05
n (-0.2231)<=-2.995
n >= 13.421
n should be atleast 14.