Probability and Statistics

If 30% of the people who shop at a local grocery store buy chocolate ice-cream, what is the probability that it will take at least 5 customers to find one who buys chocolate ice-cream?  Which simulation design has an appropriate device and a correct trial for this problem?

• Roll a fair die where 1,2, and 3 are buying chocolate ice-cream and the other numbers are not buying chocolate-ice cream. Roll the die until you get a 1,2,3. Record the number of rolls it took you.

• Using a random digits table select one digit numbers where 0-2 is a customer who buys chocolate ice cream and 3-9 is a customer who does not. Keep selecting one digit numbers until you get a 0-2. Record the number of digits selected

• Using a random digits table select one digit numbers where 0-3 is a customer who buys chocolate ice cream and 4-9 is a customer who does not. Keep selecting one digit numbers until you get a 0-2. Record the number of digits selected.

• Spin a spinner that is split up into 5 sections, where 1 section is a success of buying chocolate ice-cream and the other four sections are not buying chocolate ice-cream. Keep spinning until you get someone that buys chocolate ice-cream. Record the number of spins it took you.

There are 4 different colored candies in a bag. So, one should have a 25% chance of picking a particular color out of the bag. After pulling out 20 candies, Sally got 8 purples, which is 40%. Predict what will happen as Sally pulls out more candies.

• The percent of purple candies will exceed 40%

• The percent of purple candies will approach 25%

• The percent of purple candies will stay around 40%

• There is not enough information to make a prediction

A small, upscale boutique examines the income of 10 random households to determine if the community will be a good location for a store. Four of the households have an income between $30,000 - $55,000. Five of the households have an income between $70,000 - $100,000. One household has an income of over $700,000. For the business to consider building a new store, the typical household income must be at least $100,000. The average income in this community is $143,000. However, the boutique decides not to build a store there. What is the LIKELY reason that the boutique chooses not to locate in the community?

• The data produces an exaggerated median because of an outlier.

• The data produces an exaggerated typical income because of an outlier.

• With a typical income of $143,000, the typical household makes too much money.

• The boutique will not locate a store in a community where everyone does not make at least $100,000.

The senior class of a high school needs to decide where to go for their senior trip. They have four choices: A cruise, a camping trip, a snorkeling trip, or to the Great Wall of China. 
Due to budget constraints they cannot survey all 800 people in the senior class so they randomly select 150 people from the class and ask them their preference. The table shows the results. 
Using the sample results, estimate the proportion of the entire population that would like to take a cruise to Bermuda.

• 0.03

• 0.14

• 0.27

• 0.55

Sam rolled a die 75 times. On 39 of those rolls, he had a 6. Which statement is TRUE when the probabilities are compared?

• The theoretical probability is twice the experimental probability.

• The experimental probability and the theoretical probability are equal.

• The theoretical probability is greater than the experimental probability.

• The experimental probability is greater than the theoretical probability.

You roll one die. What is the probability that you roll a 6?

• 1/2

• 1/4

• 2/6

• 1/6

Avery tosses a coin 100 times. It lands on heads 60 times and on tails 40 times. What is the experimental probability that it will land on heads?

• 1/2

• 2/3

• 3/5

• 3/4

Jamal has the following choices for his pizza: white sauce or red sauce, white cheese or yellow cheese, mushrooms, pepperoni or sausage. What is the probability that he creates a pizza that has red sauce and white cheese?

• 1/12

• 1/2

• 1/3

• 1/4

A bag contains 1 yellow ball and 9 red balls. A ball is chosen at random from the bag. What is the BEST answer for the probability of drawing the yellow ball?

• impossible

• unlikely

• very likely

• certain

What is the probability of pulling a red marble out of a jar of marbles that have 10 green marbles, 7 red marbles and 3 blue marbles?

• 1/7

• 7/20

• 7/10

• 3/10