## Precalculus (6th Edition) Blitzer

The difference between the average numbers of awakenings during the night for 25-year-old men and 25-year-old women, as observed from the graph, is $1.9$.
We can observe that from the line graph, that for 25-year-old men, the average number of awakenings during nights is $3.4$. Similarly, it can be seen from the graph that for 25-year-old women, the average number of awakenings during nights is $1.5$. So, the difference between the average numbers of awakenings during the night for 25-year-old men and 25-year-old women will be: $3.4-1.5=1.9$.