SOLUTION: Sales of Plasma TV's in the US were about 1.8 billion in 2000, and 4 billion in 2004. Let t=0 correspond to 2000 and find a model for this data. According to this model, what are s

Algebra ->  Coordinate Systems and Linear Equations -> SOLUTION: Sales of Plasma TV's in the US were about 1.8 billion in 2000, and 4 billion in 2004. Let t=0 correspond to 2000 and find a model for this data. According to this model, what are s      Log On


   

Question 810484: Sales of Plasma TV's in the US were about 1.8 billion in 2000, and 4 billion in 2004. Let t=0 correspond to 2000 and find a model for this data. According to this model, what are sales in 2016?
t=16 corresponds to 2016
That's where I got stuck.
Answer by josmiceli(19441) About Me  (Show Source):
You can put this solution on YOUR website!
You can use the general point-slope formula
The given points are:
( 0, 1.8 ) and ( 4, 4 )
Time in years are plotted on the horizontal axis and
billions of sales are plotted on the vertical axis
--------------
+%28+s+-+4+%29+%2F+%28+t+-+4+%29+=+%28+1.8+-+4+%29+%2F+%28+0+-+4+%29+
This is ( change in y ) / ( change in x ) = ( change in y ) / ( change in x )
+%28+s+-+4+%29+%2F+%28+t+-+4+%29+=+-2.2+%2F+%28-4%29+
++%28+s+-+4+%29+%2F+%28+t+-+4+%29+=+1.1%2F2+
+2%2A%28+s+-+4+%29+=+1.1%2A%28+t+-+4+%29+
+2s+-+8+=+1.1t+-+4.4+
+2s+=+1.1t+%2B+3.6+
+s+=+.55t+%2B+1.8+
-----------------
You are asked to find the point ( 16, s )
+s+=+.55%2A16+%2B+1.8+
+s+=+8.8+%2B+1.8+
+s+=+10.6+
There will be 10.6 billion in sales in 2016
check:
++%28+s+-+4+%29+%2F+%28+t+-+4+%29+=+1.1%2F2+
++%28+10.6+-+4+%29+%2F+%28+16+-+4+%29+=+1.1%2F2+
+6.6+%2F+12+=+1.1%2F2+
+2%2A6.6+=+12%2A1.1+
+13.2+=+13.2+
OK
Here's the plot of the line:
+graph%28+400%2C+400%2C+-2%2C+20%2C+-2%2C+14%2C+.55x+%2B+1.8+%29+