First, we need to find the total ratio of the nieces:
3 + 7 = 10
Next, we need to find the fraction of the total ratio that each niece receives:
3/10 for the younger niece
7/10 for the older niece
To find out how much each niece will receive this year:
Younger niece: 3/10 × $320 = $96
Older niece: 7/10 × $320 = $224
To find out how much more the younger niece will receive in 5 years:
In 5 years, the younger niece will be 8 years old and the older niece will be 12 years old.
The new ratio will be:
8 + 12 = 20
So, the younger niece will receive:
3/20 × $320 = $48
To find the difference:
$48 - $96 = -$48
Therefore, the younger niece will receive $48 less in 5 years than she receives this year.