The rate of change of stamp collection was $57.5 per year.
Rate is comparison of two related quantities.
Often the second quantity is time (per second, per hour, etc) but it can be anything.
Can be in the style "this per that" or as a single number calculated using division.
Example: Sam makes 3 pancakes every 6 minutes, that is a rate of:
• 3 pancakes per 6 minutes
• 0.5 pancakes per minute
• 30 pancakes per hour
• an hourly rate of 30
By formula the rate of change = Change in cost/ Time taken
=( $980 - $420)/ 8years
= $460/ 8 years
= $57.5 per year
Thus the rate of change of stamp collection was $57.5 per year.
Learn more about rate here :
https://brainly.com/question/12786410
#SPJ4
