A nationwide survey in 2001 revealed that U. S. grade-school children spend an average of µ = 8.0 hours per week doing homework. The distribution is normal with σ = 2.5. Last year, a sample of n = 100 grade-school children was given the same survey. For this sample, the mean number of homework hours was 7.4. Has there been a significant change in the homework habits of grade-school children? Test with α = .05. What are the 7 steps ?

f(x) is going down by 4

step-by-step explanation:

(its either that or its going left by 4)

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