AMOUNT OF BACTERIA PRESENT
Time Amount
1:00 P.M. 14.0 grams
4:00 P.M. x grams
7:00 P.M. 18.4 grams
Data for a certain biology experiment are given in the table above. If the amount of bacteria present increased by the same fraction during each of the two 3-hour periods shown, how many grams of bacteria were present at 4:00 P.M.? Choose the most appropriate option:
A) 14.0  B) 16.1  C) 16.0  D) 12.3  E) 12.4
The question says that bacteria increased by same fraction, not by same amount in 2 intervals of 3 hours.   Let X represent the amount of bacteria present at 4:00 PM. Since the fractional increase must remain constant from 1 to 4pm as it is from 4pm to 7pm:   Fractional increase from 1 PM to 4 PM = X / 14.0   Fractional increase from 4 PM to 7 PM = 18.4 / X   X \ 14 = 18.4 \ X   X^2 = 18.4 * 14   X = 16   answer : 16.0
<result>C</result>
AMOUNT OF BACTERIA PRESENT
Time Amount
1:00 P.M. 14.0 grams
4:00 P.M. x grams
7:00 P.M. 18.4 grams
Data for a certain biology experiment are given in the table above. If the amount of bacteria present increased by the same fraction during each of the two 3-hour periods shown, how many grams of bacteria were present at 4:00 P.M.?