Using a linear function, we have that:
a) The percentage will be 47% during the year of 2001.
b) The predicted percentage in 2005 is of 44.97%.
<h3>What is a linear function?</h3>
A linear function is modeled by:
y = mx + b
In which:
- m is the slope, which is the rate of change, that is, by how much y changes when x changes by 1.
- b is the y-intercept, which is the value of y when x = 0, and can also be interpreted as the initial value of the function.
The percentage in 1980 is considered as the initial amount, hence b = 58.8. In 15 years, the percentage decreased from 58.8% to 50.5%, hence the slope is given by:
m = (50.5 - 58.8)/15 = 0.5533.
Hence the percentage in t years after 1980 is given by:
P(t) = 58.8 - 0.5533t.
Item a:
This is t + 1980, for which P(t) = 47, hence:
P(t) = 58.8 - 0.5533t
47 = 58.8 - 0.5533t.
0.5533t = 11.8.
t = 11.8/0.5533
t = 21.3.
1980 + 21 = 2001, hence the percentage will be 47% during the year of 2001.
Item b:
2005 is 25 years after 1980, hence the percentage is P(25), given as follows:
P(25) = 58.8 - 0.5533x25 = 44.97%.
More can be learned about linear functions at brainly.com/question/24808124
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