Graphics Interpretation - Scatterplots and Bubble Graphs
The graph shows GDP per capita (in 2010 US dollars) and Internet users as a percentage of population for 35 Latin American and Caribbean countries in 2010. The relative size of each circle represents each country's population in 2010.
From each drop-down menu, select the option that creates the most accurate statement based on the information provided.
[[dropdown1]] % more countries have a per-capita GDP less than $15,000 than have a per-capita GDP greater than $15,000.
For the six most populous countries, the percentage of the population that are Internet users has a range of about [[dropdown2]] %.
Incorrect.
You might have gotten this value if you miscounted the number of countries with a per-capita GDP greater than $15,000.
First find the number of countries with a per-capita GDP greater than $15,000. Since there are 35 countries in the graph, you can subtract this value from 35 to find the number of countries with a per-capita GDP less than $15,000.
Next, use the following formula to find the percent that one value is greater than the other.
$$\mbox{Percent change} = \frac{\mbox{Difference}}{\mbox{Original}} \cdot 100\%$$
Incorrect.
You might have gotten this value if you divided the number of countries with a per-capita GDP less than $15,000 by the number of countries with a per-capita GDP greater than $15,000 and converted the result to a percentage. You need to use the percent change formula.
First find the number of countries with a per-capita GDP greater than $15,000. Since there are 35 countries in the graph, you can subtract this value from 35 to find the number of countries with a per-capita GDP less than $15,000.
Next, use the following formula to find the percent that one value is greater than the other.
$$\mbox{Percent change} = \frac{\mbox{Difference}}{\mbox{Original}} \cdot 100\%$$
Right!
In the graph, notice that there are five countries with a per-capita GDP greater than $15,000.
Since there are 35 countries in the graph, the remaining 30 countries must have a per-capita GDP less than $15,000.
Next, use the following formula to find the percent change.
$$\mbox{Percent change} = \frac{\mbox{Difference}}{\mbox{Original}} \cdot 100\%$$
You are considering the percent increase when you go from five countries to 30 countries. Thus, the difference is $$30-5=25$$ and the original value is 5.
$$\frac{25}{5} = 5=500\%$$
Incorrect.
You might have gotten this answer if you found the range for all of the countries, instead of the range for just the six most populous countries.
The problem states that the relative size of each circle represents the corresponding country's population. Locate the circles for the six most populous countries by finding the six largest circles.
You can use the vertical axis to estimate the Internet-users percentage for each of these six countries. Make sure to use the center of each circle when estimating this value. Finally, calculate the range by subtracting the highest value minus the lowest value.
Incorrect.
You might have gotten this answer if you found the mean (average) of the Internet-users percentage for the six most populous countries, instead of their range.
The problem states that the relative size of each circle represents the corresponding country's population. Locate the circles for the six most populous countries by finding the six largest circles.
You can use the vertical axis to estimate the Internet-users percentage for each of these six countries. Make sure to use the center of each circle when estimating this value. Finally, calculate the range by subtracting the highest value minus the lowest value.
Incorrect.
You may have gotten this answer if you incorrectly found the percentage of Internet users for the six most populous countries. You should use the center of the circle to find this percentage.
The problem states that the relative size of each circle represents the corresponding country's population. Locate the circles for the six most populous countries by finding the six largest circles.
You can use the vertical axis to estimate the Internet-users percentage for each of these six countries. Make sure to use the center of each circle when estimating this value. Finally, calculate the range by subtracting the highest value minus the lowest value.
The highest percentage is about 45% and the lowest is about 30%, so the range of values is approximately $$45\%-30\%=15\%$$.
