Build a box plot from 11 reading times
Eleven students wrote down how many minutes they read last night. Let's turn their data into a box plot.
Here are their times, already in order from least to greatest.
The smallest value is fifty and the largest is ninety-five.
The middle value — the median — is the sixth one in the list: seventy-five.
Q1 is the middle of the lower half. The middle of fifty, sixty, sixty-five, seventy, and seventy is sixty-five.
Q3 is the middle of the upper half. The middle of eighty, eighty-five, eighty-five, ninety, and ninety-five is eighty-five.
Now we draw a number line that covers our data, from forty to one hundred.
Plot all five numbers: min, Q1, median, Q3, and max.
Connect Q1 and Q3 to make a box. The box holds the middle fifty percent of the data.
Draw a vertical line through the box at the median.
Stretch whiskers from the box out to the smallest and largest values.
The whiskers show the full range. The box shows the middle half — half the readers fell between sixty-five and eighty-five minutes.
That's our box plot — five numbers tell the whole story of the data!
Now you try. Read the median on this box plot. What is the median?