Question

After one week a music downloading site sold over 80,000 songs. After 4 weeks the music downloading site sold over 300,000 songs. Find the average rate of change of songs per week.

75,000 songs per week

80,000 songs per week

55,000 songs per week

73,334 songs per week

Answer 1

The rate changed by 220,000. Divide by 4 to get an average weekly rate.
220,000=55,000

Answer 2

why wouldn't you divide by 3 instead of 4?

Answer 3

^ you would divide by 3, not 4, since the change takes place over three weeks

(300,000-80,000)/3 = 73,334 (rounded)

Answer 4

or, more generally:

rate of change = (number of CDs on week 4-number of CDS on week 1)/(4-1)

Answer 5

ok thank you