The absolute hearing threshold for the 23 participants is given below:
• 25,22,18,35,37,34,31,27,24,21,18,39
,
• 36,17,17,17,32,32,35,35,32,32,29
To distribute the data into 5 classes with an initial class boundary of 16.5, and ending class boundary of 41.5, we calculate the class width below.

Thus, the data is distributed in the table below:
Next, we plot the histogram: