Given, in the problem,
Less than 82 degrees F, the turtles hatched will be 'male'.
Greater than 88 degrees F, the turtles hatched will be 'female'.
Since we need a 'mixture' of males and females, we need to hatch in the region that is less than 82 degrees and greater than 88 degrees.
We can put two "hollow" circles at 82 degrees and 88 degrees, respectively (since these temperatures are NOT included), and put two arrows in two directions.
The number line is shown below: