For margin of error to be a maximum of 3:
3 = z*(SD / sqrt(n)), where z is the z-score, SD is the standard deviation and n is the sample size.
z = 1.96 for a 95% confidence interval, and we are given SD = 15.
3 = 1.96*15/sqrt(n)
sqrt(n) = 9.8
n = 96.04 ~ 96 commercials.
Answer:

Step-by-step explanation:
<u>Given</u>
<u />
<u>Solution</u>
(1) Find the rate of the cube's edge length with respect to time at s=30:

(2) Find the rate of the cube's surface area with respect to time at s=30:

Therefore, the surface area increases when the length of an edge is 30 cm at a rate of
.
Answer:
y = - 3x + 5
Step-by-step explanation:
The equation of a line in slope- intercept form is
y = mx + c ( m is the slope and c the y- intercept )
Calculate m using the slope formula
m = (y₂ - y₁ ) / (x₂ - x₁ )
with (x₁, y₁ ) = (3, - 4) and (x₂, y₂ ) = (1, 2)
m =
=
= - 3, thus
y = - 3x + c ← is the partial equation
To find c substitute either of the 2 points into the partial equation
Using (1, 2), then
2 = - 3 + c ⇒ c = 2 + 3 = 5
y = - 3x + 5 ← equation of line