Answer:
1500z
Step-by-step explanation:
Given a bacteria population that is multiplied by z every hour, and the population after 2 hours is 1500, you want the population after 3 hours in terms of z.
Application
The problem statement tells you the population is multiplied by z every hour. After 2 hours, the population is 800 +300 +400 = 1500. After 3 hours, that value will be multiplied by z:
1500z . . . . . population after 3 hours
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Additional comment
The given values of population tell us z = 1100/800 = 1.375 for the first hour, and z = 1500/1100 ≈ 1.364 for the second hour. The average value of z for the two-hour period is √(15/8) ≈ 1.369. The desired expression could be any of ...
- 800z³ . . . . . . . population 3 hours after the beginning
- 1100z² . . . . . . . population 2 hours after the first hour
- 1500z . . . . . . . population 1 hour after the second hour
Presumably z would have different values in each case, and we hesitate to predict what those values might be. Perhaps the population is being rounded to the nearest 10 or 100.
An exponential regression calculation models the population as ...
p = 801.945×1.36812^t . . . . . . . z ≈ 1.36812
Using this formula, we get the given population numbers by rounding to the nearest 10.
