Answer:
t =1.453 decades from 1980 i.e in year 1994.5
Step-by-step explanation:
Given:
- Population @ year 1980 P = 678.97 thousands.
- Population @ year 2000 P = 776.73 thousands.
- The rate of increase is linear - constant rate.
Find:
As the population of San Francisco was revitalizing, for what value of the independent variable t did it reach 750 thousand ?
Solution:
- Develop an expression of population P as a function of time t in decades elapsed from year 1980 on-wards
- The linear expression can take a form of :
P(t) = m*t + C
- Where, m is the rate of increase.
C is the initial population.
- Formulate m:
m = (776.73 - 678.97) / 2 = 48.88
- Formulate C:
C = P (@ 1980) = 678.97
- Evaluate P(t) = 750:
P(t) = 48.8*t + 678.97
750 = 48.8*t + 678.97
t = 71.03/48.8
t =1.453 decades
