Alex is saving money because she would like to purchase the new video gaming system, after 2 weeks of saving she has $47 after 24 weeks of saving she has $430, approximately how many dollars per week did alex save on average between weeks 2 and 24?
a. $15.96 per week
b. $17.41 per week
c. $17.91 per week
d. $19.88 per week