Statistics: Probability Rules

In an AP Statistics class, 57% of students eat breakfast in the morning, 80% of them floss their teeth, and 46% of the students do both.  What is the probability that a randomly chosen student eats breakfast but does not floss their teeth?

• 9%
• 11%
• 34%
• 91%

In an AP Statistics class, 57% of students eat breakfast in the morning, 80% of them floss their teeth, and 46% of the students do both.  What is the probability that a randomly chosen student eats breakfast or flosses their teeth?

• 91%
• 9%
• 11%
• 34%

Five juniors and four seniors have applied for two open student council positions, and administrators have decided to pick two new members randomly.  What is the probability that they are both from the same grade?

• .395
• .444
• .506
• .569

A fair coin has come up "heads" 10 times in a row.  The probability that the coin will come up heads on the next flip is:

• greater than 50%, it's due to happen.
• 50%
• less than 50%, since tails is happening so much.
• Can't be determined

According to the National Telecommunication and Information Administration, 50.5% of U.S. households had internet access in 2001.  What is the probability that four randomly selected U.S. all had internet access in 2001?

• 6.5%
• 12.6%
• 49.5%
• 50.5%

Pepsi is running a sales promotion in which 12% of all bottles have a "FREE" logo under the cap.  If you buy a 6-pack of bottles, what is the probability that you will find at least 1 "FREE" logo?

• .464
• .536
• .12
• 0

Political analysts estimate the probability that Hillary Clinton will run for president in 2008 is 45%, and the probability that NY's Governor George Pataki will run as the Republican candidate is 20%.  If their political decisions are independent, what is the probability that only Hillary runs for president? 

• 9%
• 11%
• 25%
• 36%

An ice cream stand owner reports that 12% of the cones they sell are "JUMBO" size.  You want to see what a "JUMBO" cone looks like so you stand and watch the sales for a while.  What is the probability that the first "JUMBO" cone is the fourth cone you see them sell?

• 8%
• 33%
• 40%
• 60%

A bicycle shop equips 60% of its bikes with a water bottle holder, and 55% of its bikes are equipped with a kick stand.  34% of the bikes have both features.  What is the probability that a randomly chosen bike has a kick stand GIVEN THAT it has a water bottle holder?

• 34%
• 56.7%
• 61.8%
• 81%

The probability of a tourist visiting an area cave is .7, and of a tourist visiting a nearby park is .6.  The probability of visiting both places on the same day is .4.  The probability that a tourist visits at least one of these two places is:

• .08
• .28
• .42
• .9