# Algebra

posted by .

The town of appleville recorded the following dates and populations.

YEAR POPULATION

1985 51.5
1985 53
1990 56
1995 62

Estimate the approximate population of Appleville in 1988 by finding an equation and then substituting.

HELP!!!

• Algebra -

Do this exactly the way w and I did the previous one

• Algebra -

• ok -

It says approximate so put it on the straight line between 1985 and 1990

what is that line?
m = (56-53)/(1990-1985) = 3/5
so y = (3/5)x + b
when x = 1985, y = 53 so
53 = (3/5) (1985) + b
53 = 1191+b
b = -1138
so
y = (3/5) x - 1138 between 1985 and 1990 approximately
y at 1988 = (3/5)(1988) - 1138
= 1192.8-1138 = 54.8 approximately

• Algebra -

Now before dinner is ready go back and understand the one w did and I explained.

• Algebra -

We can find this equation using different methods (Least square method, Lagrange interpolation polynomial method, ...)
Which you are applying?

• Algebra -

What is did here is called "linear interpolation" and I suspect it is what your text wants looking at the level of your previous problem. We could get more sophisticated fitting these four points with a cubic polynomial but based on the other problem I am quite sure your class is not there yet. I am quite sure by approximate they mean fit with a straight line between the closest points, linear interpolation.

• Algebra -

Yes Mgraph, but look at the previous question further down. I think this class is on straight lines. I could be wrong of course.

• Algebra -

I can not see them solving for a least square fit or using Lagrange polynomials.

## Similar Questions

1. ### college algebra

4. The yearly cost T, in thousands of dollars, of tuition and required fees at a private college (includes two- and four-year schools and does not include room and board) can be approximated by T= 3/5n + 5 where n is the number of …
2. ### Algebra 1

i need help working these correctly! 1. Are the inequalities 3x-4<10-4x and 2(x-5) >3(2x-6) equivalent?
3. ### calculus

I solved this problem, can someone check it to make sure I did it right. There are two parts to this intrepation and estimate of the value. Let C(t) be the total value of the US currency (coins and banknotes) in circulation at time, …
4. ### Algebra

The town of Appleville recorded the following dates and populations. YEAR POPULATION (in thousands) 1980 51.5 1985 53 1990 56 1995 62 Estimate the approximate population of Appleville in 1988 by finding an equation and then substituting.
5. ### algebra

write the equation for this situation the population, p, in thousands,can be approximated by the sum of 4 and one-half times the years since 1985,d. Then graph the equation and use the graph to determine the population in the town …
6. ### math

In a particular small town, the population in 1995 was 1200. Ever since then the population has grown by 4% every year. If conditions stay the same, what is the approximate expected population in the year 2000?
7. ### math

In a particular small town, the population in 1995 was 1200. Ever since then the population has grown by 4% every year. If conditions stay the same, what is the approximate expected population in the year 2000?
8. ### Pre-Calculus

A town has a population which is growing linearly. In 1970 its population was 36,000 while in 1985 its population was 63,000. Find a formula for its population P(t), where t=0 corresponds to the year 1970.
9. ### algebra

The population of a particular country was 29 million in 1985; in 1997, it was 38 million. The exponential growth function describes the population of this country t years after 1985. Use the fact that 12 years after 1985 the population …
10. ### Math

The population of a town is modelled by P=-0.1x^2+1.2x+4.4 where x is the number of years since the year 2000, and y is the population in thousands. a) In the year 2005, what is the population?

More Similar Questions