Question 4·Easy·One-Variable Data Distributions; Measures of Center and Spread
The dot plot shows the walking times, in minutes, for a group of students traveling to school.
Which choice is the median walking time?
For median questions from a dot plot, do not try to estimate. Count the total number of dots to determine the position of the middle value, then scan from left to right, keeping a running count until you land on that middle position.
Hints
Use the definition of median
The median is the middle value after the data are put in order from least to greatest.
Decide which value is in the middle
First count how many dots there are in the plot. If there are dots, the median is the 5th value.
Accumulate counts from left to right
Start at the smallest time and keep a running total of dots until you reach the middle one.
Desmos Guide
Enter the data values
From the dot plot, enter the walking times into a list, repeating values to match the number of dots (for example, appears twice and appears three times):
L=[6,7,7,8,9,9,9,10,11]
Compute the median
Type median(L) and read the result shown by Desmos.
Step-by-step Explanation
Count the data points
Count the dots in the plot. There are total walking times, so the median is the 5th value when the times are listed in order.
Identify the middle value
List the values in order using the dot plot counts:
The 5th value is , so the median walking time is 9 minutes.