Probability review---Block 1

Saryiah is conducting an experiment using a bag of marbles. For each trial of the experiment, she takes 1 marble from the bag without looking. She records the color and then replaces the marble in the bag. The table shows the results of 60 trials of the experiment.

Blue = 15

Green = 25

yellow = 20

Saryiah will conduct 20 more trials of the experiment. Based on the results in the table, approximately how many of those marbles will be blue?

• 17

• 13

• 20

• 40

Na'zya is conducting an experiment in which she draws a straw. Some of the straws are short, and some are long. For each trial, she draws a straw, records the result, and replaces the straw. The table shows the results of 60 trials of the experiment.

Long = 12

Short = 48

Na'zya will conduct 30 more trials of the experiment. Based on the results in the table, how many of these additional trials will have a result of a short straw being drawn?

• 24

• 48

• 12

• 56

Each year in middle school, students are randomly assigned to one of 4 electives. The probability of a random student being assigned to each elective is shown below:

Art = 0.01

Band= 0.002

Chorus = 0.357

Computers = ????

If every student is assigned to an elective, what is the probability that a student is assigned to computers?

• 0.361

• 0.006

• 0.212

• 0.631

Each year in middle school, students are randomly assigned to one of 4 electives. The probability of a random student being assigned to each elective is shown below:

Art = 0.01

Band= 0.002

Chorus = 0.357

Computers = ????

If every student is assigned to an elective, what percentage of students chose computers?

• 63%

• 6%

• 21%

• 36%

At Kennedy Middle School, students have several options for lunch each day. For the main dish, students can choose a hamburger, pizza, chef's salad, or grilled chicken sandwich. For a side item, students can choose either an apple, carrot sticks, or potato puffs. For dessert, students can choose either a cookie or a pumpkin pie. Each student will also receive either a carton of lowfat milk, bottle of water or a can drink. How many different variations can students choose for their main dish, side item, dessert, and drink?

• 24

• 72

• 36

• 42

Christopher has a bag with orange, yellow, and blue chips in it. Without looking, he reaches into the bag and removes a chip. He records the color and returns the chip to the bag. He performs this experiment 40 times. The table shows the data he collects.

Orange = 12

Yellow = 15

Blue = 13

Based on the information in the table, how many orange chips should Christopher expect to select out of the bag after repeating this experiment 80 times?

• 40

• 60

• 20

• 24

Hailey recreated an experiment in which the probability of drawing a red card from a stack of red, blue, yellow, green and purple cards is 1/5. She draws a card, records it, replaces it, and then draws another card and continues this procedure 100 times. At the end of her experiment she notices that she has drawn a red card 42 times. Which of the following statements is true about Hailey’s experiment?

• Hailey's results are the same as the predicted results.

• Hailey’s results are lower than the predicted results.

• Hailey’s results are higher than the predicted results.

• Hailey's deck of cards contains more red cards.

Why is the following statement incorrect?

The probability of snow on next Wednesday is 375%.

• A probability cannot be more than 100%.

• A probability of 375% is possible but unlikely.

• The statement does not tell where it might snow.

• It never snows in Charlotte before Christmas.

A student is taking a multiple-choice test that has 90 questions. Each question has six answer choices. If the student guesses randomly on every question, how many questions should the student expect to answer correctly?

• 12

• 9

• 15

• 10

The table lists the probability of four events occurring.

A -------- 0.09

B---------0.80

C---------0.30

D---------0 . 01

Which event is least likely to occur?

• A

• D

• C

• B