Respuesta :

Answer:

The cost in 7 years will be of $384.69.

Step-by-step explanation:

Equation for exponential decay:

The equation for an amount after t years is given by:

[tex]A(t) = A(0)(1-r)^t[/tex]

In which A(0) is the initial value and r is the decay rate.

The cost of High Definition television now averages $1200, but the cost is decreasing by about 15% percent per year.

This means that [tex]A(0) = 1200, r = 0.15[/tex]. So

[tex]A(t) = A(0)(1-r)^t[/tex]

[tex]A(t) = 1200(1-0.15)^t[/tex]

[tex]A(t) = 1200(0.85)^t[/tex]

What will the cost be in 7 years?

This is A(7).

[tex]A(t) = 1200(0.85)^t[/tex]

[tex]A(7) = 1200(0.85)^7 = 384.69[/tex]

The cost in 7 years will be of $384.69.