Answer:
(a) Profit function P(x) = 0.02x^2+60x-80
(b) Average profit P(x)/x = P/x = 0.02x+60-80/x
Marginal profit dP/dx = 0.04x+60
Step-by-step explanation:
Cost function: C(x) = -0.02x^2+40x+80
Price function: p(x) = 100
(a) The profit function P(x) = x*p(x)-C(x) can be expressed as:

(b)Average profit function: P(x)/x

Marginal profit function: dP/dx

Answer:
32 Liters
Step-by-step explanation:
In the glass tank:
W = represents the volume of water Andrei uses (in liters)
n =Number of marbles
Given that: 
The volume of the glass tank is the volume of the water in the tank plus the total volume of n marbles added.
Therefore:

Volume of the tank =32 Liters
You haven't provided the series, therefore, I can only help with the concept.
<u><em>For an infinite geometric series, we have two possibilities for the common ratio (r):</em></u>for r > 1, the terms in the series will keep increasing infinitely and the only possible logic summation of the series would be infinity
for r < 1, the terms will decrease, therefore, we can formulate a rule to get the sum of the infinite series
<u><em>In an infinite series with r < 1, the summation can be found using the following rule:</em></u>sum =

where:
a₁ is the first term in the series
r is the common ratio
<u>Example:</u>
For the series:
2 , 1, 0.5 , 0.25 , ....
we have:
a₁ = 2
r = 0.5
Therefre:
sum =

Hope this helps :)
The interquartile range<span> (</span>IQR<span>) is a measure of variability, based on dividing a </span>data set<span>into quartiles. Quartiles divide a rank-ordered </span>data set<span> into four equal parts. The values that divide each part are called the first, second, and third quartiles; and they are denoted by Q1, Q2, and Q3, respectively.</span>
Distance = rate times time.
414= .75x
414/.75
552 miles per hour