0.1 Review exercises (ch 3-13)  (Page 7/12)

79. Find the probability that one randomly chosen child is in the 6th grade and prefers fried shrimp.

1. $\frac{32}{70}$
2. $\frac{8}{32}$
3. $\frac{8}{8}$
4. $\frac{8}{70}$

80. Find the probability that a child does not prefer pizza.

1. $\frac{30}{70}$
2. $\frac{30}{40}$
3. $\frac{40}{70}$
4. 1

81. Find the probability a child is in the 5 ^th grade given that the child prefers spaghetti.

1. $\frac{9}{19}$
2. $\frac{9}{70}$
3. $\frac{9}{30}$
4. $\frac{19}{70}$

82. A sample of convenience is a random sample.

1. true
2. false

83. A statistic is a number that is a property of the population.

1. true
2. false

84. You should always throw out any data that are outliers.

1. true
2. false

85. Lee bakes pies for a small restaurant in Felton, CA. She generally bakes 20 pies in a day, on average. Of interest is the number of pies she bakes each day.

1. Define the random variable X .
2. State the distribution for X .
3. Find the probability that Lee bakes more than 25 pies in any given day.

86. Six different brands of Italian salad dressing were randomly selected at a supermarket. The grams of fat per serving are 7, 7, 9, 6, 8, 5. Assume that the underlying distribution is normal. Calculate a 95% confidence interval for the population mean grams of fat per serving of Italian salad dressing sold in supermarkets.

87. Given: uniform, exponential, normal distributions. Match each to a statement below.

1. mean = median ≠ mode
2. mean>median>mode
3. mean = median = mode

Chapter 10

Use the following information to answer the next three exercises: In a survey at Kirkwood Ski Resort the following information was recorded:

Suppose that one person from [link] was randomly selected.

88. Find the probability that the person was a skier or was age 11–20.

89. Find the probability that the person was a snowboarder given he or she was age 21–40.

90. Explain which of the following are true and which are false.

1. Sport and age are independent events.
2. Ski and age 11–20 are mutually exclusive events.
3. P (Ski AND age 21–40)< P (Ski|age 21–40)
4. P (Snowboard OR age 0–10)< P (Snowboard|age 0–10)

91. The average length of time a person with a broken leg wears a cast is approximately six weeks. The standard deviation is about three weeks. Thirty people who had recently healed from broken legs were interviewed. State the distribution that most accurately reflects total time to heal for the thirty people.

92. The distribution for X is uniform. What can we say for certain about the distribution for $\overline{X}$ when n = 1?

1. The distribution for $\overline{X}$ is still uniform with the same mean and standard deviation as the distribution for X .
2. The distribution for $\overline{X}$ is normal with the different mean and a different standard deviation as the distribution for X .
3. The distribution for $\overline{X}$ is normal with the same mean but a larger standard deviation than the distribution for X .
4. The distribution for $\overline{X}$ is normal with the same mean but a smaller standard deviation than the distribution for X .

93. The distribution for X is uniform. What can we say for certain about the distribution for ${\displaystyle \sum X}$ when n = 50?

1. distribution for ${\displaystyle \sum X}$ is still uniform with the same mean and standard deviation as the distribution for X .
2. The distribution for ${\displaystyle \sum X}$ is normal with the same mean but a larger standard deviation as the distribution for X .
3. The distribution for ${\displaystyle \sum X}$ is normal with a larger mean and a larger standard deviation than the distribution for X .
4. The distribution for ${\displaystyle \sum X}$ is normal with the same mean but a smaller standard deviation than the distribution for X .