Years Since 1970, x: 0, 10, 20, 30, 40
Population (In thousands), y: 589, 801, 1,202, 1,998, 2,959
Find the population for 1975.
A. 623 thousand people.
B. 599 thousand people
C. 513 thousand people
D. 650 thousand people
To find the population for 1975, we can estimate using the data provided for the years 1970 and 1980.
Population in 1970: 589 thousand people
Population in 1980: 801 thousand people
We can estimate a linear relationship between the years and population:
Slope = (801 - 589) / (1980 - 1970) = 212 / 10 = 21.2
Using the formula for a line: y = mx + b, where y is the population, m is the slope, x is the year, and b is the y-intercept.
y = 21.2x + b
Substituting the values:
589 = 21.2(0) + b
b = 589
So the equation becomes:
y = 21.2x + 589
Now, to find the population for 1975 (x = 5):
y = 21.2(5) + 589
y = 106 + 589
y = 695 thousand people
Therefore, the closest option is:
D. 650 thousand people