Question 10·Easy·One-Variable Data Distributions; Measures of Center and Spread
A researcher recorded the number of birds seen during five different 10-minute observations at a park.
The bar graph shows the number of birds seen in each observation.
Which choice is the mean number of birds seen per observation?
For a mean from a graph, treat each bar height as a data value: add all the values shown, then divide by how many values there are. Keep track of the number of bars so you divide by the correct count.
Hints
Read the bar heights
Write down the number of birds for each of the five observations shown by the bars.
Find the total
Add the five numbers to get the total number of birds seen across all observations.
Compute the mean
Divide the total by because there are five observations.
Desmos Guide
Enter the data as a calculation
In an expression line, type (6+9+5+8+12)/5.
Read the result
Desmos will display the value of the expression. That value is the mean number of birds per observation.
Step-by-step Explanation
Add the values from the bar graph
From the graph, the counts are , , , , and .
Add them: .
Divide by the number of observations
There are observations, so the mean is .
Therefore, the correct answer is 8.