Chi Ap Stat

The following list shows the selling prices of 8 houses in a certain town.

What is the median selling price of the houses in the list?

• $263,200

• $283,300

• $288,450

• $290,600

• $293,400

Administrators at a state university computed the mean GPA (grade point average) for juniors and seniors majoring in either physics or chemistry. The results are displayed in the table below. When juniors and seniors are grouped together, could physics majors have a higher mean GPA than chemistry majors?

• No. The physics majors’ mean GPA for juniors and seniors must be 3.0, while the chemistry majors’ mean GPA for juniors and seniors must be 3.3.

• No. There is not enough information to determine the mean GPA for each major, but it must be higher for chemistry majors than for physics majors.

• Yes. It could happen. Whether it does happen depends on the number of juniors and seniors in each major.

• Yes. It could happen. Whether it does happen depends on the variability of the GPAs within each of the four groups of students.

• Yes. It could happen. Whether it does happen depends on the shapes of the distributions of the GPAs for each of the four groups of students.

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 in the chart. 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.

A statistician at a metal manufacturing plant is sampling the thickness of metal plates. If an outlier occurs within a particular sample, the statistician must check the configuration of the machine. The distribution of metal thickness has mean 23.5 millimeters (mm) and standard deviation 1.4 mm. Based on the two-standard deviations rule for outliers, of the following, which is the greatest thickness that would require the statistician to check the configuration of the machine?

• 19.3 mm

• 20.6 mm

• 22.1 mm

• 23.5 mm

• 24.9 mm

Which of the following is the best estimate of the standard deviation of the distribution shown in the figure?

• 5

• 10

• 20

• 30

• 4

The tail length of Siberian tigers is approximately normally distributed with a mean of 0.85 meter and a standard deviation of 0.13 meter. Which of the following is the best interpretation of the z-score for a particular Siberian tiger with a tail length of 0.8 meter?

• The tiger’s tail length is approximately 0.38 standard deviation below the mean.

• The tiger’s tail length is approximately 0.38 standard deviation above the mean.

• The tiger has an approximate 0.38 probability of having a tail length of 0.8 meter.

• The tiger’s tail length is approximately 0.0065 meter greater than the standard deviation.

• The tiger’s tail length is approximately 0.05 meter below the mean

For a certain population of penguins, the distribution of weight is approximately normal with mean 15.1 kilograms (kg) and standard deviation 2.2 kg Approximately what percent of the penguins from the population have a weight between 13.0 kg and 16.5 kg?

• 17%

• 34%

• 57%

• 68%

• 74%

Zucchini weights are approximately normally distributed with mean 0.8 pound and standard deviation 0.25 pound. Which of the following shaded regions best represents the probability that a randomly selected zucchini will weigh between 0.55 pound and 1.3 pounds?

• 
• 
• 
• 
• 

At a small coffee shop, the distribution of the number of seconds it takes for a cashier to process an order is approximately normal with mean 276 seconds and standard deviation 38 seconds. Which of the following is closest to the proportion of orders that are processed in less than 240 seconds?

• 0.17

• 0.25

• 0.36

• 0.83

• 0.95

An international polling agency estimates that 36 percent of adults from Country X were first married between the ages of 18 and 32, and 26 percent of adults from Country Y were first married between the ages of 18 and 32. Based on the estimates, which of the following is closest to the probability that the difference in proportions between a random sample of 60 adults from Country X and a random sample of 50 adults from Country Y (Country X minus Country Y) who were first married between the ages of 18 and 32 is less than 0 (negative) ?

• 0.001

• 0.2843

• 0.1268

• 0.0566

• 0.8732