Comparing Distributions

Which display would you prefer to use to determine the median?

• box plot

• line plot

• stem and leaf

Answer explanation

The box plot displays the median without having to do any calculations.

The appropriate measure of spread for a data set that is skewed is...

• range

• standard deviation

• IQR

Answer explanation

The IQR gives a consistent measure of variability for skewed as well as normal distributions.

The _________ can be used to determine the interquartile range. (IQR)

• line plot

• box plot

• histogram

Answer explanation

The box plot is divided into quartiles. The IQR can be easily determined from it.

Given the following distributions, which has the highest median?

• Red

• Purple

• Black

Students in a statistics class participated in a project in which they attempted to estimate the true mean height of all students in their large high school. The students were split into 4 groups. Each group had their own sampling method, and they used it to select a sample each day for 50 days. Shown above are the estimates based on their 50 samples. After the samples were collected and the means were plotted the teacher visited the school nurse who told her that the true mean height of all students in the school is 67.5 inches. Which group produced sample statistics that estimated the true value of the parameter with relatively low bias and low variability?

• Group 1

• Group 2

• Group 3

• Group 4

Given the following distributions, which has the smallest IQR?

• Red

• Purple

• Black

Given the following distributions, which is symmetric?

• Red

• Purple

• Black

Given the following distributions, which is skewed to the left?

• Red

• Purple

• Black

Given the following distributions, which is skewed to the right?

• Red

• Purple

• Black

Given a set of symmetric data, which of the following is an appropriate measure of spread?

• Mean

• Median

• Standard Deviation

• Interquartile Range (IQR)