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1. Which of these is a correct description of the term?
2. The president of an online music streaming service whose customers pay a fee wants to gather additional information about customers who have joined in the past 12 months. The company plans to send out an e-mail survey to a sample of current customers with a link that gives participants a month of streaming service for free once the survey has been completed. They know that musical tastes vary by geographical region. Which of the following sample plans would produce the most representative sample of its customers?
3. The reason we check that npand n(1 - p) are at least 10 when calculating probabilities in a binomial situation is to:
4. A maker of breakfast cereals plans to run a promotion in which an action figure is included in each box of cereal. The more popular figures will appear in fewer boxes. The probability of getting a box with each kind of toy is shown in the table below.
What is the probability that the first two randomly selected boxes contain Serenity and Blackstar?
5. A department store has a promotion in which it hands out a "scratchcard" at the checkout register, with a percent discount concealed by an opaque covering. The customer scratches off the covering and reveals the amount of the discount. The table below shows the probability that a randomly selected card contains each percent discount.
What is the expected value of the percentage of discount?
6. In basketball, an offensive rebound occurs when a player shoots and misses, and a player from the same team recovers the ball. For the 176 players on the roster for one season of professional men's basketball, the third quartile for the total number of offensive rebounds for one season was 143. If five players are selected at random (with replacement) from that season, what is the approximate probability that at least three of them had more than 143 rebounds that season?
7. A new smartwatch is manufactured in one part of a factory, then secured for shipping in another, independent part of the factory. The weight of the smartwatch has a mean of 62 grams and a standard deviation of 1.0 grams. The weight of the packaging (box, user's guide, bubble wrap, etc.) has a mean of 456 grams and a standard deviation of 6 grams. Together, the distribution of the weight of the smartwatch and its packaging would have the following mean and standard deviation:
8. Students in a small high school were asked to vote for a meal for a school event. The results of the survey and the grades of the students are summarized below.
Are the events Student is a juniorand Student chose pizzaindependent?
9. The total cholesterol level in a large population of people is strongly skewed right with a mean of 210 mg/dL and a standard deviation of 15 mg/dL. If random samples of size 16 are repeatedly drawn from this population, which of the following appropriately describes the sampling distribution of these sample means?
10. In one metropolitan region, technical writers have an annual salary that is approximately normally distributed with a mean of $55,800. The first quartile of salaries is $48,815. What is the standard deviation?