Identify the percent of change as an increase or decrease. Then find the percent of change. Round to the
nearest tenth of a percent, if necessary.
15 books to 21 books

Respuesta :

Answer:

40% increase

Step-by-step explanation:

from 15 to 21 is an increase

old value = 15

new value = 21

formula is:  (new value - old value) / old value x 100

[(21 - 15) / 15] x 100 = 6/15 x 100

= 2/5 x 100

= .4 x 100

= 40%