Binomial and Geometric

If you were to flip a coin 20 times, what is the probability you would get at least 13 heads?

• 94.23%

• 13.16%

• 5.77%

• 7.39%

You are a terrible driver. Whenever you drive, there is a 70% chance that you will run over a pedestrian. If you go for a drive 15 times, what is the probability that you will run over no more than 6 pedestrians?

• 0.985

• 0.015

• 0.988

• 0.012

The American Red Cross says that about 11% of the U.S. population has Type B blood. A blood drive is being held at your school. What is the probability that at least 2 of the first 10 blood donors has Type B blood? 

• 0.088

• 0.697

• 0.214

• 0.303 

Is this binomial experiment? Shuffle a deck of 52 cards. Turn over the top card. Put the card back in the deck, shuffle again. Repeat the process 50 times. Let X = the number of aces you observe.

• Yes

• No, the trials are not independent.

• No, there are more than 2 outcomes

If you want a certain number of successes in a set amount of trials, use the ????? model.

• geometric

• binomial

• normal

• calculato

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

• 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

Out of the whole population in the US, 13% are left-handed. If the population follows a geometric distribution, how many people would you need to sample, on average, before obtaining the first left-handed person?

• 3.9 people

• 7.69 people

• 26.1 people

• none of these

A wildlife biologist examines frogs for a genetic trait they suspect may be linked to sensitivity to industrial toxins in the environment. Previous research had established that this trait is usually found in 1 of every 8 frogs. 

1. The biologist collects and examines a dozen frogs. If the frequency of the trait has not changed, what’s the probability they find the trait in none of the 12 frogs? 

• Binomial Distribution

• Geometric Distribution