158k views
3 votes
K

The table shows data from 1975 and projections to 2050 of the number of millions of people age 15 to 59 in a country.
Complete parts (a) and (b) below.
Labor Pool
Year
(millions)
1975 490
1980 560
1985 650
720
1990
1995
760
2000
800
y-x+xX+0
(Type integers or decimals rounded to three decimal places as needed.)
Labor Pool
(millions)
840
Year
Labor Pool
Year
(millions)
2005 865 2035
2010 900 2040
2015 920
800
2045
2020 920 2050 670
2025
830
915
2030
875
a. What is the quadratic function that best models this population as a function of the number of years after 1970? Let x represent the number of years after 1970 and y represent the number of
millions of people in this labor pool.

1 Answer

1 vote

Answer:

Explanation:

To find the quadratic function that models the population, we can use quadratic regression. We can assign the variable x as the number of years after 1970, and y as the labor pool in millions of people. We can then input the data into a calculator or a spreadsheet software and use regression analysis to find the quadratic equation that best fits the data.

Using a spreadsheet software, we can input the data and use the trendline feature to find the quadratic function. The resulting equation is:

y = -32.917x^2 + 338.958x + 63.396

Therefore, the quadratic function that best models this population as a function of the number of years after 1970 is:

y = -32.917x^2 + 338.958x + 63.396

where x is the number of years after 1970 and y is the number of millions of people in this labor pool.

b. According to the model, what is the projected size of the labor pool in 2025?

To find the projected size of the labor pool in 2025, we need to plug in x = 55 (since 2025 is 55 years after 1970) into the quadratic function we found in part (a):

y = -32.917x^2 + 338.958x + 63.396

y = -32.917(55)^2 + 338.958(55) + 63.396

y = -32.917(3025) + 18642.19 + 63.396

y = -99588.508 + 18642.19 + 63.396

y = -80982.922

Rounding to the nearest million, we get a projected size of the labor pool in 2025 of 83 million. Therefore, according to the model, the projected size of the labor pool in 2025 is 83 million.

User Scott Willeke
by
7.8k points