I was looking at the answer for Why P=MC instead of MR=MC? The willingness of the customer to pay should decrease with each additional unit because of the law of diminishing returns, which makes me think it should be MR=MC in equilibrium.
TR = P*Q = 400Q-4Q^2.
MR = dTR/dQ = 400-8Q.
400-8Q=140.
260=8Q.
Q = 32.5 units.

P = 400 - 4Q
= 400 - 4*32.5
= 400 - 130
= $270

Maybe I don't know when to use price instead of marginal revenue. What am I missing?

Which of these is not a result of regular exercise

When sending a claim to an insurance company for services provided by the physician, why are both icd-10 and cpt codes required to be submitted? how are these codes dependent upon each other? what would be the result of not submitting both codes on a medical claim to an insurance company?

Stocks a, b, and c are similar in some respects: each has an expected return of 10% and a standard deviation of 25%. stocks a and b have returns that are independent of one another; i.e., their correlation coefficient, r, equals zero. stocks a and c have returns that are negatively correlated with one another; i.e., r is less than 0. portfolio ab is a portfolio with half of its money invested in stock a and half in stock b. portfolio ac is a portfolio with half of its money invested in stock a and half invested in stock c. which of the following statements is correct? a. portfolio ab has a standard deviation that is greater than 25%.b. portfolio ac has an expected return that is less than 10%.c. portfolio ac has a standard deviation that is less than 25%.d. portfolio ab has a standard deviation that is equal to 25%.e. portfolio ac has an expected return that is greater than 25%.