Question

The chart below shows one store's sales of computers, listed by model.
2 circle graphs. A circle graph titled May. Poreg, 262; Quilren, 282; Dinztop, 223; Quilren 2, 135; Juvanto, 148. A circle graph titled June. Poreg, 173; Quilren, 184; Dinztop, 148; Quilren 2, 153; Juvanto, 212.
If the changes in sales between May and June continue at the same rate, how many total computers will be sold in July?
a.
534
b.
721
c.
1,019
d.
1,254

Answer 1

First compute the totals and the month-to-month change.

May total = 262 + 282 + 223 + 135 + 148 = 1,050
June total = 173 + 184 + 148 + 153 + 212 = 870

If the absolute changes continue at the same rate (i.e., July = June + (June − May)), the net monthly change = 870 − 1,050 = −180, so
July total = 870 + (−180) = 690.

690 is not one of the answer choices you gave. (If instead you meant the same percent change for each model, the projected July total ≈ 810.6 — also not listed.)

Please check the numbers on the charts (or upload a picture). With the numbers you wrote, the correct projected July total is 690.