Question

In 1960, the life expectancy in the UK was 71.1 years. In 2008, it was 79.9 years. Let F(t) = life expectancy and t = the number of years since 1960.
a) Find a linear function that fits the data.
b) Use the function of Part (a) to estimate the life expectancy in 2010.

Show your work not just the final answer.

Answer 1

You just top posted, but you're not the only one. I gave you all the clues you needed. Post what I wrote again and I'll help you more.

Answer 2

So ... a linear function is of the form f(x) = mx + c.

Draw a graph with the data in this problem: you have two points (x,y) = (1960, 71.1) and (x,y) = (2008,79.9)

Now get a ruler and draw the straight line through these points. What is the slope of this curve m? Now solve for c.

Can you do that much?

Answer 3

lol yes i can thank you

Answer 4

Tell me what values of m and c you get.

Answer 5

i got 8.8 and 48

Answer 6

i did y2-y1 over x2-x1

Answer 7

That's correct in principle, but you have made some sort of error

(y2-y1)/(x2-x1) = (79.9 - 71.1)/(2008-1960) = .... NOT 8.8 but ...

Answer 8

9?

Answer 9

Seriously? Cmon. Do the math.

Answer 10

m = (y2-y1)/(x2-x1) = (79.9 - 71.1)/(2008-1960) = 8.8/48 = 0.1833.

Now, solve for c.

Answer 11

oh i c. I was skipping a step...but i do not know hwo to solve for c, that is why i am here

Answer 12

f(x) = mx + c. So c = f(x) - mx for all x.

Take x = 1960. Then f(x) = 71.1 and hence
c = f(x) - mx = ....

Answer 13

if i am adding i got 2031

Answer 14

or 1888

Answer 15

Look at the formula and substitute:
c = f(x) - mx = 71.1 - (0.1833)x(1960) = 71.1 - 359.3 = -288.3

This means you now know the linear function f(x) = mx + c, as you know both m and c.

Clear?