What is the value of the fourth term in a geometric sequence for which a1=15 and r=1/3

Formula: an = a1(r)^n-1

n = term number

a1 = first term

r = rate

Plug our values in:

n = 4

a1 = 15

r = 1/3

a4 = 15(1/3)^4-1

a4 = 15(1/3)^3

a4 = 15(1/27)

a4 = 0.5555555556

a4 = 0.6 to the nearest tenth

answer: 204

step-by-step explanation:

we are told that the revenue is

x⋅(4080−10x)=−10x^2+4080x

this is a quadratic function, so to maximize it we should find the x-value of its vertex. recall that the x-value of the vertex of the parabola ax^2+bx+c is given by the formula −b/2a.

so in this case, we have a=−10 and b=4080, so the x-value of the vertex is

−b/2a= −(4080)/2(−10)=204