At 1:00 pm, there were 10.0 grams of bacteria. The bacteria increased to x grams at 4:00 pm, and 28.9 grams at 7:00 pm. If the amount of bacteria present increased by the same fraction during each of the 3-hour periods, how many grams of bacteria were present at 4:00 pm?  Select the correct option: A) 16.2 B) 16.4 C) 16.6 D) 16.8 E) 17.0
Let x be the factor by which the bacteria increases every three hours.   At 4:00 pm, the amount of bacteria was 10x and at 7:00 pm it was 10x^2.   10x^2 = 28.9   x^2=2.89   x=1.7   At 4:00 pm, the amount of bacteria was 10(1.7)=17 grams.   The answer is 17.0.
<result>E</result>
At 1:00 pm, there were 10.0 grams of bacteria. The bacteria increased to x grams at 4:00 pm, and 28.9 grams at 7:00 pm. If the amount of bacteria present increased by the same fraction during each of the 3-hour periods, how many grams of bacteria were present at 4:00 pm?