Final answer:
The number of bacteria after t hours, given a starting population of 7000 that doubles every 3 hours, is described by the exponential growth expression N(t) = 7000 × 2^(t/3).
Step-by-step explanation:
The question involves creating an expression for a bacteria population that doubles every 3 hours. This type of growth is categorized as exponential growth. The general form of the exponential growth model is N(t) = N0 × 2t/d, where N(t) is the population at time t, N0 is the initial population, and d is the doubling time in the same time units as t. Starting with 7000 bacteria, and knowing they double every 3 hours, the expression for the number of bacteria after t hours is:
N(t) = 7000 × 2t/3
This expression can be used to calculate the number of bacteria at any given time t, by simply substituting the value of t (in hours) into the expression.