Let Upper C left-parenthesis q right-parenthesis represent the cost, Upper R left-parenthesis q right-parenthesis the revenue, and pi left-parenthesis q right-parenthesis the total profit, in dollars, of producing q items.(a) If Upper C prime left-parenthesis 50 right-parenthesis equals 75 and Upper R prime left-parenthesis 50 right-parenthesis equals 88, approximately how much profit is earned by the 51 Superscript st item?The profit earned from the 51 Superscript st item will be approximately dollar-sign.(b) If Upper C prime left-parenthesis 90 right-parenthesis equals 71 and Upper R prime left-parenthesis 90 right-parenthesis equals 67, approximately how much profit is earned by the 91 Superscript st item?The profit earned from the 91 Superscript st item will be approximately dollar-sign

(a)$13

(b) Loss of $4

Step-by-step explanation:

C(q) represents Cost of producing q units.

R(q) represents Revenue generated from q units.

P(q) represents Total Profit made from producing q units.

Marginal analysis is concerned with estimating the effect on quantities such as cost, revenue, and profit when the level of production is changed by a unit amount. For example, if C(q) is the cost of producing q units of a certain commodity, then the marginal cost, MC(q), is the additional cost of producing one more unit and is given by the difference

MC(q) = C(q + 1) − C(q).

Using the estimation

C'(q)≈=C(q+1)-C(q)

We find out that MC(q)=C'(q)

We can therefore compute the marginal cost by the derivative C'(q).

This also holds for Revenue, R(q) and Profit, P(q).

(a) If C'(50)=75 and R'(50)=88

51st item.

P'(50)=R'(50)-C'(50)

=88-75=$13

The profit earned from the 51st item will be approximately $13.

(b) If C'(90)=71 and R'(90)=67, approximately how much profit is earned by the 91st item.

P'(90)=R'(90)-C'(90)

=67-71= -$4

The profit earned from the 91 st item will be approximately -$4.

There was a loss of $4.

a. the residual plot for model 1 has a random pattern and is a good fit for the data.

answer: 88

step-by-step explanation: