SOLUTION: Sorry guys I did not finish my last post out. I am new here. This is a repost with the question I need. In 1993, the life expectancy of males in a certain country was 73.6 yea

Algebra ->  Coordinate Systems and Linear Equations  -> Linear Equations and Systems Word Problems -> SOLUTION: Sorry guys I did not finish my last post out. I am new here. This is a repost with the question I need. In 1993, the life expectancy of males in a certain country was 73.6 yea      Log On


   

Question 1083314: Sorry guys I did not finish my last post out. I am new here. This is a repost with the question I need.
In 1993, the life expectancy of males in a certain country was 73.6 years. In 1998​, it was 77.2 years. Let E represent the life expectancy in year t and let t represent the number of years since 1993
The linear function​ E(t) that fits the data is
​E(t)equals=____+_____ Rounded to the nearest tenth

Answer by josmiceli(19441) About Me  (Show Source):
You can put this solution on YOUR website!
Plot +E+ on the vertical axis
Plot +t+ on the horizontal axis
---------------------------------
Call year 1993 +t+=+0+
That makes 1998 +t+=+5+
So, you are given the 2 points:
( 0, 73.6 )
( 5, 77.2 )
--------------------
You can use the general point-slope formula
+%28+77.2+-+E+%29+%2F+%28+5+-+t+%29+=+%28+77.2+-+73.6+%29+%2F+%28+5+-+0+%29+
+%28+77.2+-+E+%29+%2F+%28+5+-+t+%29+=+3.6+%2F+5+
Multiply both sides by +5%2A%28+5+-+t+%29+
+5%2A%28+77.2+-+E+%29+=+3.6%2A%28+5+-+t+%29+
+386+-+5E+=+18+-+3.6t+
+5E+=+3.6t+%2B+368+
+E+=+.72t+%2B+73.6+
---------------------------
check answer:
Does it go through ( 5, 77.2 ) ?
+E+=+.72t+%2B+73.6+
+77.2+=+.72%2A5+%2B+73.6+
+77.2+=+3.6+%2B+73.6+
+77.2+=+77.2+
OK
Does it go through ( 0, 73.6 ) ?
+E+=+.72t+%2B+73.6+
+73.6+=+.72%2A0+%2B+73.6+
+73.6+=+73.6+
OK