Binomial vs Geometric

The owner of a small convenience store is trying to decide whether to discontinue selling magazines. He suspects that only 5% of the customers buy a magazine and thinks that he might be able to use the display space to sell something more profitable. What is the probability that at least 5 of his first 50 customers buy magazines?

• 0.104

• 0.896

• 0.066

• 0.774

counts the number of successes in a fix number of trails. X = 0,1,2,3,…,n

• Geometric

• Binomial

• Both

• Neither

counts the number of trials needed to obtain the 1st success. X = 1,2,3,…

• Geometric

• Binomial

• Both

• Neither

Each observation falls into one of two categories: “success” or “failure”

• Geometric

• Binomial

• Both

• Neither

If we want to calculate the probability of rolling a 6 for the first time on the 6^th roll of a die, would we use the geometric or the binomial distribution?

• geometric

• binomial

The n observations are all independent.

• Geometric

• Binomial

• Both

• Neither

The probability of success, p, is the same for each observation.

• Geometric

• Binomial

• Both

• Neither

A restaurant offers a game piece with each meal to win coupons for free food. The probability of a game piece winning is 1out of 4 and is independent of other game pieces winning. A family orders 4 meals. Let C be the number of coupons the family wins.

What type of variable is C?

• Geometric

• Binomial

• Both

• Neither

Alma wrote a phone app. She has noticed that 3% of the users who download her app upgrade it the same day. Let N be the number of customers who download Alma's app until one upgrades it on the same day. Assume that the probability of each user's upgrades are independent.What type of variable is N?

• Geometric

• Binomial

• Both

• Neither

Leo selects 25 grandparents at random from his town to interview. In the town, 35% of the grandparents have their grandchildren living with them. Let G be the number of grandparents Leo interviews whose grandchildren are living with them. What type of variable is G?

• Geometric

• Binomial

• Both

• Neither