2.2 Exam 3: chapters 5, 6, & 7

Which graph best describes the distribution?

• A

• B

• C

• D

Find the probability that a randomly selected seventh–grade student spends less than $4 a day on food.

• A

  0.7981

• B

  0.2019

• C

  0.9999

• D

  0.0001

85% of the seventh–grade students spend more than what amount per day?

• A

  $2.12

• B

  $0.75

• C

  $4.74

• D

  $0.41

If one student is randomly chosen, what is the probability that the student does intermediate algebra homework at least 2 hours per day?

• A

  0.7475

• B

  0.4259

• C

  0.2525

• D

  0.6784

60% of these students spend at most how many hours doing their homework?

• A

  1.69 hours

• B

  1.31 hours

• C

  1.5 hours

• D

  0.2533 hours

Find the probability that the weight of supplies carried by one randomly chosen llama is between 60 and 70 pounds.

• A

  0.4441

• B

  0.5559

• C

  0.8944

• D

  1

The middle 50% of weights of supplies carried by a randomly chosen llama is between _____ and _____.

• A

  0 and 62.5 pounds

• B

  58.45 and 66.55 pounds

• C

  56.5 and 68.5 pounds

• D

  There is not enough information given.

Which of the following are true for the normal distribution?

• I

  More values fall close to the mean than fall far away from the mean.

• Ii

  The mean and standard deviation cannot be the same.

• Iii

  A change in µ causes the graph to shift to the left or right and changes the shape of the graph.

• Iv

  A change in s causes a change in the shape of the normal curve.

• A

  I, IV

• B

  I, II, III, IV

• C

  I, II, III

• D

  III, IV

Find the probability that the randomly selected student sleeps less than 8 1/2 hours per night.

• A

  .2143

• B

  0.7727

• C

  0.4705

• D

  0.375

Find the probability that the randomly selected student sleeps eight to twelve hours per night.

• A

  0

• B

  1

• C

  0.75

• D

  0.25

On average, how long does a junior high school student sleep per night?

• A

  .2143

• B

  0.7727

• C

  0.4705

• D

  0.375

On average, how long does a junior high school student sleep per night?

• A

  9.6 hours

• B

  6.5 hours

• C

  7.8 hours

• D

  8.4 hours

We are interested in the probability that a randomly selected student sleeps less than eight hours, knowing that he/she sleeps less than ten. Which graph best depicts this situation?

• A

• B

• C

• D