Mock Information

Question 1

What does Consumer Surplus mean?

Answer 1

Consumer surplus is the difference between the maximum amount that a client is capable of paying and what they end up actually paying. This is seen as the EXTRA BENEFIT that a consumer gain by not spending as much money as they thought.

Question 2

What is the Producer Surplus?

Answer 2

The Producer Surplus means that the Producer could have charged less for its good. By charging more they got more monetary compensation = EXTRA BENEFIT for the producers.

Question 3

In a Graph where can we find the Producer Surplus?

Answer 3

Under the line of the equilibrium and above the supply curve.

Question 4

In a Graph, where can we find the Consumer Surplus?

Answer 4

Above the line of price equilibrium and below the demand curve.

Question 5

What is the formula to the Consumer Surplus?

Answer 5

The consumer surplus is calculated by the difference between what one can pay and what one actually pays, multiplies by quantity in equilibrium (also called QUANTITY SOLD) and divided by 2.

Question 6

What is the formula to the Producer Surplus?

Answer 6

The Producer Surplus is calculated as the difference between the price that was actually sold and the minimum price they could charge, multiplied by the quantity actually sold, and divided by 2.

Question 7

How do I find the critical points of a multivariate equation?

Answer 7

To find the critical points of a multivariate equation, you have to solve all the partial derivatives and then you equal to 0.

Question 8

What is the meaning of the Marginal Product Capital?

Answer 8

The Marginal Product Capital measures how much an output (in profit or q) varies if you change the Capital resources. Labour stays constant.

Question 9

Why do we have jumps in the ecdf graph?

Answer 9

We have jumps in the ecdf graph because they indicate discrete variables.

Question 10

How do we know when a boxplot is right or left skwed?

Answer 10

We look at where it is more concentrated. If it is more concentrated it has a smaller piece. Thus, if it is more concentrated on the bottom towards the bottom line, then it is more empty on the upper part. We can then conclude it is right skewed (focus on the left).
If it is closer to the upper quartile then it is left skewed because it is more concentrated towards the right (upper part).

Question 11

If looking at a box-plot, I ask you about the first quartile or the upper quartile, or any quartile, what should you refer to?

Answer 11

If in a box-plot they ask me about any quartile I always have to look at the box, never at the wiskers.

Question 12

If I have f(x-c) in which direction is the function moving?

Answer 12

The function is moving c to the right.

Question 13

If I have f(x+c) in which direction is the function moving?

Answer 13

The function will be moving c to the left.

Question 14

How do we find the aproximation of a function with Taylor’s formula? Which sequence do we have to go through?

Answer 14

First we derive until the second derivative the function. Then we substitute all ‘As’ with the value we have which could be x=1. Then we obtain a function that is composed of our previous derivatives multiplied by x-a to the power of etc.

Question 15

When I am looking for which of the two solutions I found optimizes cost, how should I proceed? Based on which criteria do I know whether it maximizes cost or profit?

Answer 15

Once I am aware of the peaks between the equilibrium of the Marginal Revenue and the Marginal Cost, I need to substitute this within the second derivative of the PROFIT function. The one that is NEGATIVE (thus profit function bending down) also increases the PROFIT MAXIMIZATION.

Question 16

What is the difference between correlation and Linear Regression?

Answer 16

Linear Regression is a model that showcases the relationship ALWAYS between a dependent and independent variable. Correlation simply measures the strenght of this relationship and its direction (positive or negative).

Question 17

How do I know when X is on a logarithmic scale?

Answer 17

X is in a logaritmic scale if the distance between the numbers seems to explonentially vary. Thus, the distances are not always the same.

Question 18

Who says that the same causes produces the same effects?

Answer 18

Isaac Newton and Laplace determinism says that the same causes produces the same effects. It is also called DETERMINISTIC CAUSALITY.

Question 19

What is the total differential?

Answer 19

The total differential showcases the relationship between two variables. How much changing variable x impact how variable y reacts?

Question 20

What is the Growth factor? What is the difference with the growth rate?

Answer 20

The Growth factor is the multiplicative increase in value over a period of time. Instead, the growth rate rappresents the percentage change over the same specific period of time.

Question 21

What is the difference between the Geometric mean and the Average growth rate?

Answer 21

The Geometric mean across a series of period and growths considers compounding across the years. The Average growth rate simply means all the growth rates from the first Yo to YT.

Question 22

What is the priority line on which variables should be differentiated in a Product Integration Rule?

Answer 22

LIPET
- Logarithms log/ln
- Inverse functions
- Polynomial x
- Exponential e^x
- Trigonometric ( sinx )

Question 23

What is interesting about the relationship between the U substitution and the chain rule?

Answer 23

The chain rule and the U substitution are similar in a sense that the U substitution is applicable to Integers while the chain rule is applicable to derivatives.

Question 24

If I need to calculate the Empirical variance for which I only have the information about the share of the elements, which formula do I use?
ex: 54% of petrol stations with a value of 1.55 in their petrol price. I need to calculate out of all these shares and their respective price, the final Empirical variance.

Answer 24

If I need to calculate the Empirical Variance (s^2) of a sequence of shares. I sum together (Observed price - Mean price)^2 * share of that Observed price.
Ex. (1.55-1.60)^2*(0.14) so I calculate the variance of 1.55 that rappresents 14% of the companies with we registered.

Question 25

What is the difference in Statistics between n N(X) and F(X)?

Answer 25

n = number of the observations N(X)= absolute cumulative frequency values of the observations per each category (ex. 6 drugged people that are 70, 7 that are 80 (because we added 1 +6)). F(X)= relative cumulative frequency (10%, 23%, 30%)

Question 26

How do we calculate the percentiles?

Answer 26

To calculate the percentiles, we first start with np. Np= percentile (0.25)*(total of observations). Then, you analize whether your answer is an integer or not. If it is an integer you add one, and you round down. Ex. 3.75+1=4.75 x(4) is gonna be my 0.25 percentile.

Question 27

Looking at the empirical correlation coefficient, when do I have a strong correlation and do I have a weak correlation?

Answer 27

Weak when r<5 Strong when r>8

Question 28

How do I find an extrema in a function? How do I classify it?

Answer 28

An extrema can be found verifying if a function derivated two times is positive or negative. If f(x)>0 then it is bending upwards (convex), if it is f(x)<0 it is bending downwards (concanve)

Question 29

How do I calculate the Marginal Product of Capital and the Marginal Product of Labour?

Answer 29

The Marginal product of Capital can be obtained by calculating the partial derivative of the Capital. The Marginal product of Labour can be obtained by calculating the partial derivative of the Labour.

Question 30

How do we reach the Profit Maximization when we are talking about multivariate functions?

Answer 30

1) Initiate by calculating the first partial derivative of x and of y 2) Equal the functions to 0 and determine the critical points 3) Verify if the critical point is a maximum of a minimum Pxx*Pyy-pxy^2

Question 31

In which categories can we allocate Elasticity? What does it rappresent?

Answer 31

Elasticity can if bigger than 1 is elastic, if smaller than 1 is unelastic. It rappresents how sensitive is one variable to the changes of another.

Question 32

What are the conditions to be able to find an inverse and how do you find the inverse?

Answer 32

The conditions to find the inverse are for a function to NOT have missing points and to NOT have two outputs or more for one input. You find the inverse by exchanging x and y and solving for y.

Question 33

What are the conditions to be able to find an integral or a derivative?

Answer 33

To be an integral or a derivative the function must not have sharp points, must be defined at point a and NOT have jumps.

Question 34

How do I solve a limit that tends to 0 compared to a limit that tends to infinite?

Answer 34

In a limit that tends to zero, I will attempt to simplify and eliminate from the denominator the x. In the limit that tends to minus or plus infinite, I will attempt to gather the highest X for example x^3, in order to place the x in the denominator and eliminate some factors.

Question 35

In which case do I use the u substitution and in which cases do i use the integration by parts?

Answer 35

The U subtitution usually has to do with the fact that the derivative of a function is placed within the integral to be solved. Thus, they are related somehow. The Integration by parts can be applicable to any two portions.

Question 36

What is the difference between Taylor's Formula and Taylor's norder aproximation?

Answer 36

Taylor's formula gives us another way of looking at a specific function. While Taylor's naproximation shows the value that a function acquires when close to point x=a.