Dr. richards is interested in conducting a psychological study with his class? he is interested in how much influence being in a fraternity or sorority has on his students' performance in class. he offers the students the opportunity to be in the study in exchange for extra credit points. any students who did not want to participate in the study were offered another option to earn the extra credit points. 148 students decide to participate in the study. dr. richards has each participant fill out a questionnaire asking them a variety of questions, including the question "are you a member or a sorority or fraternity? " once dr. richards collects and analyzes the data, he finds that students who are members of a sorority or fraternity do not perform as well in class as those who are not members of a sorority or fraternity. dr. richards is conducting a(n) study.

Case

Explanation:

A case study is a research method that observes a subject with respect to the environmental context.

Here, Dr. Richards is trying to find out how much influence does being in a  fraternity or sorority have on a student's performance. Here, the environment is whether they are in a fraternity or sorority and the observed value is their performance.

Hence, Dr. Richards is conducting a case study.

all of them lol cause theres no map

marginal cost is a microeconomic measure that us to evaluate the extent to which the level of production of a good is sustainable in accounting, that is, to how many quantities the company plans to profit from the production of the good.

the concept of marginal cost is simple, it means the cost of producing one more item. for example, in the case of pies, the marginal cost is the cost of producing one more pie than those that have already been produced.

it is important to understand that productive activity influences marginal cost. the marginal cost of some goods can be very high, while others may be insignificant. for example, the marginal cost of producing an extra plane is very high. already the marginal cost of a water company to provide 1l more water is derisory.

in the case of pies, the cost involves the inputs, the labor and the fixed cost, which involves the fixed space of the bakery. the level of production initially has the marginal cost decreasing because there is space and manpower available. however, to produce more you have to hire more workers and buy more inputs. if physical space is limited, workers will conflict with places, inputs and their productivity will decrease, meaning there is an optimum point of production for each level of space and manpower. from this point on, the productivity of the workers will be getting smaller because of lack of space, so that the marginal cost of producing one more pie will be increasing. so, although you have not posted the chart, but if you have the answer, you can see that my explanation goes according to the marginal cost curve that will increase from the 4th pie, answer (c).