Answer:
-19/60
Step-by-step explanation:
You want the rational number halfway between -1/3 and -3/10.
The average of two numbers is the number halfway between them. It is their sum, divided by two.
Effectively, you are being asked for the average of -1/3 and -3/10.
[tex]\text{average }=\left(-\dfrac{1}{3}-\dfrac{3}{10}\right)\times\dfrac{1}{2}=-\dfrac{1\cdot10+3\cdot3}{3\cdot10\cdot2}=\boxed{-\dfrac{19}{60}}[/tex]