Q: If 75 out of 104 students own more than 2 pairs of shoes, what percent is this? Round to the nearest whole number.

$$ \frac{75}{104} \times 100 \approx 72\% $$

Question 1

Which of the following best describes a quantitative variable?

Accepted Answer

A variable that represents a numerical value, such as the number of pairs of shoes owned.

Question 2

When constructing a stemplot, why is it important to include stems even if they have no data values?

Accepted Answer

To ensure the stemplot accurately represents gaps in the data.

Question 3

A stemplot of the number of pairs of shoes owned by students is skewed right. What does this indicate about the data?

Accepted Answer

Most students own a low number of pairs of shoes, with a few owning much more.

Question 4

Given the following stemplot stems: 0, 1, 2, 4, 5, which stem is missing and should be included for completeness?

Accepted Answer

3

Question 5

If 75 out of 104 students own more than 2 pairs of shoes, what percent is this? Round to the nearest whole number.

Accepted Answer

$$ \frac{75}{104} 	imes 100 \approx 72\% $$

Question 6

Which of the following is NOT a key feature to describe when comparing distributions?

Accepted Answer

Color of the data points

Question 7

A stemplot is rotated 90 degrees counterclockwise. What type of plot does it resemble?

Accepted Answer

A histogram

Question 8

In a back-to-back stemplot comparing seat belt use in primary and secondary enforcement states, what is the main advantage of this display?

Accepted Answer

It allows direct comparison of the two distributions on the same scale.

Question 9

Suppose a stemplot of seat belt usage rates in 50 states shows one state with a much lower rate than the others. What statistical term best describes this state?

Accepted Answer

Outlier

Question 10

If you split each stem in a stemplot (e.g., 0-4 and 5-9), what is the primary effect on the display?

Accepted Answer

It provides a more detailed view of the data's shape.

Question 11

A stemplot of the number of pairs of shoes owned by students has a key: 3|2 = 32 pairs of shoes. What does the '3' represent in this key?

Accepted Answer

The stem, representing the tens digit

Question 12

Which of the following best describes the center of a distribution?

Accepted Answer

The typical or middle value, such as the median

Question 13

In the context of seat belt usage rates, which of the following would be the best method to compare the distributions of primary and secondary enforcement states?

Accepted Answer

Construct a back-to-back stemplot

Question 14

If a distribution is described as 'skewed left', what does this mean?

Accepted Answer

The left tail is longer; most data are on the right.

Question 15

A stemplot is constructed for the number of pairs of shoes owned by students. The stems are 0, 1, 2, 3, 4, and 5. The leaves for stem 3 are missing. What should you do?

Accepted Answer

Include the stem 3 with no leaves to show a gap in the data.

Question 16

Which of the following is a correct interpretation of an outlier in a real-world context, such as seat belt usage rates?

Accepted Answer

An outlier is a data point that is much higher or lower than the rest, possibly indicating a unique situation in that state.

Question 17

If the stemplot for seat belt usage in primary enforcement states is more tightly clustered than in secondary enforcement states, what does this suggest?

Accepted Answer

Primary enforcement states have less variability in seat belt usage rates.

Question 18

Which of the following is the correct formula to calculate the percentage of students who own more than 2 pairs of shoes, given $$n$$ students in total and $$k$$ students who own more than 2 pairs?

Accepted Answer

$$ \frac{k}{n} 	imes 100 $$

Question 19

A stemplot is used to display the number of pairs of shoes owned by students. If the data is split into two groups (e.g., 0-4 and 5-9), what is the main purpose of this split?

Accepted Answer

To provide a clearer view of the distribution's shape.

Describing and Comparing Distributions Using Stemplots

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