AP Statistics Chapter 1 (MC) Mini-Quiz

You measure the age (years), weight (pounds), and breed (beagle, golden retriever, pug, or terrier) of 200 dogs. How many variables did you measure?

• 1

• 2

• 3

• 200

• 203

You open a package of Lucky Charms cereal and count how many there are of each marshmallow shape. The distribution of the variable "marshmallow" is:

• The shape: star, heart, moon, clover, diamond, horseshoe, balloon.

• The total number of marshmallows in the package.

• Seven--the number of different shapes that are in the package.

• The seven different shapes and how many there are of each.

• Since "shape" is a categorical variable, it doesn't have a distribution.

A review of voter registration records in a small town yielded the following table of the number of males and females registered as Democrat, Republican, or some other affiliation.

The proportion of males that are registered as Democrats is

• 300

• 30

• 0.33

• 0.30

• 0.15

Which of the following is NOT true for all distributions ?

• In a perfectly symmetric distribution, the mean and median are equal.

• About fifty percent of the scores in a distribution are between the first and third quartiles.

• In a perfectly symmetric distribution, the median is halfway between the first and third quartiles.

• The median is always greater than the mean.

• The range is always the difference between the largest and smallest observation in the data set.

When drawing a histogram, it is important to

• have a separate class interval for each observation to get the most informative plot.

• make sure the heights of the bars exceed the widths of the class intervals so that the bars are true rectangles.

• label the vertical axis so the reader can determine the counts or percent in each class interval.

• leave large gaps between bars, allowing for comments.

• scale the vertical axis according to the variable whose distribution you are displaying.

A set of data has a mean that is much larger than the median. Which of the following statements is most consistent with this information?

• The distribution is is symmetric.

• The distribution is skewed left.

• The distribution is skewed right.

• The distribution is bimodal.

• The distribution probably has several low outliers.

The pictured boxplot is of the birth weights (in ounces) of a sample of 160 infants born in a local hospital. About 40 of the birth weights were below how many ounces?

• 92

• 102

• 112

• 122

• 132

A sample of production records for an automobile manufacturer shows the following figures for production of cars per shift: 705 700 690 705

The sample's variance is approximately

• 8.66

• 7.07

• 75.00

• 50.00

• 20.00

You catch 10 cockroaches in your bedroom and measure their lengths in centimeters. Which of these sets of numerical descriptions are all measured in centimeters?

• median length, variance of lengths, largest length

• median length, first and third quartiles of lengths

• mean length, standard deviation of lengths, median length

• mean length, median length, variance of lengths

• more than one response is correct

A policewoman records the speeds of cars on a certain section of roadway with a radar gun. The pictured histogram shows the distribution of speeds for 251 cars. Which of the following measures of center and spread would be the best ones to use when summarizing this data distribution?

• Mean and interquartile range

• Mean and standard deviation

• Median and range

• Median and standard deviation

• Median and interquartile range