Unit 7 Study Guide

Marshall works at an animal shelter. He makes sure all the cats are vaccinated. In July, 56 of the cats entering the shelter had already been vaccinated. Based on this result, he predicts that if 100 cats entered the shelter, 80 of the cats would have already been vaccinated. How many cats entered the animal shelter in July?

• 56

• 100

• 80

• 70

Which probabilities are very likely? Choose all the correct answers.

• 1/2

• 1/9

• 11/12

• 2/5

• 15/17

A bin at a farmer’s market has 18 peaches, 12 apples, 15 pears, and 9 bananas. Rosa picks a piece of fruit at random from the bin. Which statement about the fruit bin is true?

• the probability of picking an apple is 2/9

• the probability of picking a peach is 5/18

• the probability of pipcking a banana is 1/7

• the probability of picking a pear is 1/3

Alexander makes dumplings. He sells orders with 1, 2, 3, or 4 dumplings. The dumplings are filled with tofu, chicken, or pork. The dumplings can be ordered boiled or fried. What is the probability that a randomly chosen order includes pork dumplings?

• 1/12
• 1/6
• 1/3
• 1/2

Dion has a container of 100 different-colored beads. He chooses a bead at random, writes down the color of the bead, and puts the bead back in the container. He does this 7 times. The colors of the beads Dion chooses are blue, blue, red, blue, green, blue, and green. Use Dion’s results to predict about how many blue beads Dion will select in the next 56 trials.

• 32 blue beads
• 40 blue beads
• 28 blue beads
• 36 blue beads

Vera is rolling two standard number cubes. What is the probability that both number cubes will show an even number?

• 1/4
• 1/2
• 1/3
• 1/6

Joaquin plays a game with a deck of cards. There are 72 action cards and 56 item cards. Joaquin selects a card at random, records whether it is an action card or an item card, and shuffles it back into the deck. In 9 trials, he selects 4 action cards and 5 item cards. Which statement about the probability of selecting an action card is correct?

• The theoretical probability is less than 1/2,and the experimental probability is

  greater than 1/2

• The theoretical probability is less than 1/2,and the experimental probability is

  less than 1/2

• The theoretical probability is greater than 1/2,and the experimental probability is

  greater than 1/2

• The theoretical probability is greater than 1/2,and the experimental probability is

  less than 1/2

Marlo rolls a number cube 12 times. The first 11 results are 1, 6, 5, 2, 4, 3, 5, 2, 1, 6,and 5. For all 12 rolls, the theoretical probability of rolling a number less than 3 is equal to the experimental probability of rolling a number less than 3. What numbers could be the result of the 12th roll? Select all that apply.

• 2

• 3

• 4

• 5

• 6

Declan asks his mom to buy a mystery pack of his favorite juice boxes. The pack has 6 juice boxes, and there are 8 possible flavors that are all equally likely. Declan wants to know the probability that at least 2 of the juice boxes will have the same flavor. Which of the following is the best simulation?

• Roll a standard number cube 8 times for each trial. Let each number represent a different flavor. Run 50 trials and find the fraction of times at least two of the same number are rolled.

• Create a spinner with 8 equal sections. Label each section with a different flavor. Spin 6 times to see if it lands on the same flavor two or more times.

• Create a spinner with 6 equal sections. Label each section with a different flavor. Spin the spinner 8 times for each trial. Run 50 trials and find the fraction of times the spinner lands on the same flavor two or more times.

• Put 8 pieces of paper in a bag, each labeled with a different flavor. For each trial, randomly select and replace a paper 6 times. Run 50 trials and find the fraction of times at least two of the same flavor appeared.

Jorge has a box with different colors of tubes of paint. In the box, there are 7 tubes of blue paint, 4 tubes of red paint, 3 tubes of yellow paint, and 6 tubes of green paint. Jorge selects a tube of paint at random. Which is more likely: selecting a tube of blue or yellow paint, or selecting a tube of green or red paint?

• Selecting a tube of blue or yellow paint
• Selecting a tube of green or red paint
• Both are equally likely
• None of the above