AP Stats MC Review 1

Of the following dotplots, which represents the set of data that has the greatest standard deviation?

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A random sample of 374 United States pennies was collected, and the age of each penny was determined. According to the boxplot below, what is the approximate interquartile range (IQR) of the ages?

• 8

• 10

• 16

• 40

• 50

The histogram above shows the number of minutes needed by 45 students to finish playing a computer game. Which of the following statements is correct?

• The distribution is skewed to the right.

• The distribution is skewed to the left.

• The distribution appears to be normal.

• The distribution appears to be chi-square.

• The distribution appears to be uniform.

A bank surveyed all of its 60 employees to determine the proportion who participate in volunteer activities. Which of the following statements is true?

• The bank should not use the data from this survey because this is an observational study.

• The bank can use the result of this survey to prove that working for the bank causes employees to participate in volunteer activities.

• The bank did not select a random sample of employees, so the survey will not provide the bank with useful information.

• The bank would have to use the survey data to construct a confidence interval in order to estimate the proportion of employees who participate in volunteer activities.

• The bank does not need to use an inference procedure to determine the proportion of employees who participate in volunteer activities because the survey was a census of all employees.

The histogram below displays the frequencies of waiting times, in minutes, for 175 patients in a dentist's office. Which of the following could be the median of the waiting times, in minutes?

• 2.50

• 7.25

• 12.25

• 15.00

• 17.50

Data were collected on the amount, in dollars, that individual customers spent on dinner in an Italian restaurant. The quartiles for these data are given below. Q1 - $36.27 Q2 - $44.27 Q3 - $58.97 Which of the following statements must be true for these customers?

• At least half of the customers spent less than or equal to $44.27 and at least half spent greater than or equal to $44.27.

• Seventy-five percent of the customers spent between $36.27 and $58.97.

• Twenty-five percent of the customers spent less than or equal to $58.97 and the remaining 75 percent spent greater than or equal to $58.97.

• The mean amount spent by customers is $44.27.

• A majority of customers spent $44.27.

The weight of adult male grizzly bears living in the wild in the continental United States is approximately normally distributed with a mean of 500 pounds and a standard deviation of 50 pounds. The weight of adult female grizzly bears is approximately normally distributed with a mean of 300 pounds and a standard deviation of 40 pounds. Approximately, what would be the weight of a female grizzly bear with the same standardized score (z-score) as a male grizzly bear with a weight of 530 pounds?

• 276 pounds

• 324 pounds

• 330 pounds

• 340 pounds

• 350 pounds

A company sells concrete in batches of 5 cubic yards. The probability distribution of X, the number of cubic yards sold in a single order for concrete from this company, is shown in the table below. The expected value of the probability distribution of X is 19.25 and the standard deviation is 5.76. There is a fixed cost to deliver the concrete. The profit Y, in dollars, for a particular order can be described by Y = 75X – 1000. What is the standard deviation of Y?

• $332.00

• $432.00

• $532.00

• $1,343.75

• $1,400.00

The manager of a public swimming pool wants to compare the effectiveness of two laundry detergents, Detergent A and Detergent B, in cleaning the towels that are used daily. As each dirty towel is turned in, it is placed into the only washing machine on the premises. When the washing machine contains 20 towels, the manager flips a coin to determine whether Detergent A or Detergent B will be used for that load. The cleanliness of the load of towels is rated on a scale of 1 to 10 by a person who does not know which detergent was used. The manager continues this experiment for many days. Which of the following best describes the manager’s study?

• A completely randomized design

• A randomized block design with Detergent A and Detergent B as blocks

• A randomized block design with the washing machine as the block

• A matched-pairs design with Detergent A and Detergent B as the pair

• An observational study

In the design of a survey, which of the following best explains how to minimize response bias?

• Increase the sample size

• Decrease the sample size

• Randomly select the sample

• Increase the number of questions in the survey

• Carefully word and field-test survey questions