Answer: My mom's height is 67.75 inches.
Step-by-step explanation: Given that my dad is 73.5 inches, I am 2.5 inches shorter than my dad. My mom is 3.25 inches shorter than me.
We are to find the height of the mom.
Since I am 2.5 inches shorter than my dad, so my height will be

Now, my mom is 3.25 inches shorter than me, so my mom's height is

Thus, my mom is 67.75 inches tall.