Answer:
For Sandra to save up and purchase the mp3 she must save additional $22.
Explanation:
This problem requires us to understand the concerns of deficit/balance
Step one
We were told that mp3 cost $95
And Sandra has saved $73
Hence for her to purchase the mp3 she has to save up to $95 which is the benchmark price for the item
Step two :
Hence the amount of money to balance up is
=Cost of mp3- Sandra's savings
= $95-$73
=$22