Question 1

In a scatterplot, the y-axis is used to label…
A) Frequency of a variable
B) observations of a variable
C) relative frequency of a variable
D) any of the above

Accepted Answer

The y-axis in a scatterplot is used to label the observations of the variable being plotted. The x-axis typically represents another variable or a numerical sequence. Frequency and relative frequency are not applicable to scatterplots as they pertain to categorical variables or discrete numerical variables, not continuous numerical variables which are typically used in scatterplots.

Question 2

Consider a data with two outcomes: yes and no. The best way to plot this data is…
A) Bar chart
B) Pie chart
C) Histogram
D) Stem-and-leaf graph

Accepted Answer

A bar chart is the best way to display data with two outcomes as it allows for a clear comparison of the number or percentage of occurrences of each outcome. A pie chart could also be used, but it may not be as effective as it can be difficult to compare the sizes of the two sections. A histogram and stem-and-leaf graph are inappropriate for this type of data as they are more appropriate for continuous data.

Question 3

Which of the following is not the right way to use a graph?
A) Time-series graphs usually have time on the x-axis
B) Pie charts are used to relative frequencies
C) Frequency polygons should be used just like bar charts
D) Histograms should have bars that are touching each other

Accepted Answer

Frequency polygons and bar charts are two different types of graphs, with frequency polygons being used to plot the shape of a distribution and bar charts being used to compare quantities. Therefore, they should not be used in the same way.

Question 4

Which would be the correct way to split the number 237 in a stem-and-leaf graph?
A) 2 would be the stem, and 37 as the leaf.
B) 23 as the stem, and 7 as the leaf.
C) 237 is the stem, there is no leaf.
D) There is no stem, and 237 are all leaf.

Accepted Answer

In a stem-and-leaf plot, the stem is the leftmost digit(s) of the number while the leaf is the rightmost digit. Therefore, the stem for 237 would be 23 and the leaf would be 7. Choice A is incorrect because the stem should only include the leftmost digit(s). Choice C is incorrect because there should be no digits in the leaf as the leaf is only the rightmost digit. Choice D is incorrect because there should always be a stem.

Question 5

Each point on scatterplot represents…
A) one observation from one variable for one individual
B) two observations from two variables for the same individual
C) the mean
D) two observations from two variables for two individuals

Accepted Answer

Each point on a scatterplot represents two observations from two variables for the same individual, allowing us to see the relationship between these two variables for each individual in the dataset.

Question 6

For each scenario, identify the best type of visualization for the data
Having two groups: Experimental and Placebo in a drug trial. A researcher wants to plot mean differences in the number of days it took for the patient to recover.

Accepted Answer

The answer of For each scenario, identify the best type...

Question 7

For each scenario, identify the best type of visualization for the data
Having the relative frequencies of the individuals' choice for car brands

Accepted Answer

The answer of For each scenario, identify the best type...

Question 8

For each scenario, identify the best type of visualization for the data
A research wants to plot the relationship between income and the number of years of education in a sample of employed workers.

Accepted Answer

The answer of For each scenario, identify the best type...

Question 9

Identify three good practices involving the use of graphs

Accepted Answer

The answer of Identify three good practices involving the use...

Question 10

Explain the difference between a frequency histogram and a bar chart. What data are they each best used for and give an example of how they are used.

Accepted Answer

The answer of Explain the difference between a frequency histogram...

Question 11

Use the following stem and leaf-plot to answer the next few questions. The data plots the temperature of the day when there were earthquakes in the last 5 years.

Accepted Answer

The answer of Use the following stem and leaf-plot to...

Question 12

Use the following stem and leaf-plot to answer the next few questions. The data plots the temperature of the day when there were earthquakes in the last 5 years.
How many observations were there?

Accepted Answer

The answer of Use the following stem and leaf-plot to...

Question 13

Use the following stem and leaf-plot to answer the next few questions. The data plots the temperature of the day when there were earthquakes in the last 5 years.
how many earthquakes occurred between 70 and 80 degrees?

Accepted Answer

The answer of Use the following stem and leaf-plot to...

Question 14

Use the following stem and leaf-plot to answer the next few questions. The data plots the temperature of the day when there were earthquakes in the last 5 years.
Identify one other way to graph this data

Accepted Answer

The answer of Use the following stem and leaf-plot to...

Question 15

Explain why graphs sometimes need to be interpreted with caution

Accepted Answer

The answer of Explain why graphs sometimes need to be...

Question 16

Below are some data about whether a sample of individuals knows how to ride a bicycle
 $$\begin{array} { c c } 
\hline \text { Participant ID } & \text { Yes or No } \
\hline 1 & \text { Yes } \
2 & \text { Yes } \
3 & \text { No } \
4 & \text { No } \
5 & \text { Yes } \
6 & \text { No } \
7 & \text { Yes } \
8 & \text { Yes } \
9 & \text { Yes } \
10 & \text { No } \
11 & \text { Yes } \
12 & \text { No } \
13 & \text { No } \
14 & \text { No } \
15 & \text { Yes } \
\hline
\end{array}$$ Is this data continuous or discrete?

Accepted Answer