Notes, abstracts, papers, exams and problems of Mathematics

Types of Data

Population and Sample

When dealing with large datasets, it's often impractical to analyze every single data point. In such instances, we collect data from a subset of the population known as a sample.

Quantitative and Categorical Data

Quantitative data represent numerical values and allow for arithmetic operations like addition, subtraction, multiplication, and division. Examples include height, weight, and temperature.

Categorical data represent categories or groups and cannot be manipulated with arithmetic operations. Examples include gender, hair color, and country of origin. We can summarize categorical data by counting the number of observations or computing the proportions of observations in each category.

Cross-Sectional and

TIGHTEN toughen

CARRY OUT complete, put into operation

TO BYPASS something that prevents people doing Something

BACKGROUND CHECKS check on the things a person has Done in the past

MEASURES reasonable limits or legislative bills

TRIGGERED made to start

OUTCOME final result

AWAIT wait with anticipation

FLOW movement, flux

BANNED forbidden, prohibited, removed

LET SOMEONE DOWN make sb disappointed by not reaching The standards

UNPICK carefully and gradually undo or remove

UNFOLDING developing, happening

FEATURE a salient quality, characteristic

FAKE false

rate of Growth speed at Which something increases in size

depreciation a decrease in price or value

shrinking getting smaller

contribute to to help to cause an event or Situation

arsenal a collection of weapons

upgrade... Continue reading "Demonic wounds.Com" »

Economic analysis: analyse the financial cost of manufacturing the product and its selling price. We study whether the materials and manufacturing procedures used are cheap or whether they make the product more expensive. We determine whether the selling price of the object is correct by comparing it to similar objects. 

Technical analysis: evaluate how the object was made. This analysis includes the study of its material the technology used to make ir, how its parts are joined together and the environmental risks of the materials used. 

Social analysis: study the object from the point of view of its social impact and analyse the human needs that it meets. We also evaluate its environmental impact and recyclability. 

Aesthetic analysis: evaluate... Continue reading "I is correct ii is correct" »

Are X and Y independent random variables?

Solution: First we calculate the marginal pdfs

Note that fX,Y (x, y) 6= fX(x) × fY (y). So they are not independent.

What is the conditional distribution of X, given Y = .50? What is the probability that less than 50% of the initiative 1 surveys are returned, given that 50% of the initiative 2 surveys are returned?

(c) Calculate E(X/Y = y). What is the expected proportion of initiative 1 surveys returned, given that 50% of the initiative 2 surveys are returned?

Three prisoners are informed by their jailer that one of them has been 1/3 1/2

First we label the prisoners as P1, P2 and P3. Suppose P1 asks the jailer to tell him privately whether P2 or P3 will be set free. Now we define the following events.

Ai... Continue reading "Probability and Statistics Problems and Solutions" »

PRINCIPLES OF DESIGN

They affect content and message.

1. Proximity

Proximity basically means space; unfortunately, most people simply try to fill up empty space. Space should be organized, so, information can be easily understood.

2. Alignment

Alignment is like rulers or margins. We need to avoid to use more than one alignment, and to use the centered alignment.

3. Repetition

There are many ways to create repetition: -Bullets, bold fonts, color, line, a design element… Repetition unifies and strengthens. It creates visual interest.

4. Contrast

There are many ways to create contrasts: -Large/small type, warm/cold colors, old/new fonts, and horizontal/vertical… Contrast has 2 purposes: 1. Create interest on a page. 2. Aid organization on a page

5.

1. The role of business statistics is to convert data into meaningful info.

Which of the following statements about the relationship between interest rates and bond prices is true?

1. There is an inverse relationship between bond prices and interest rates.
2. There is a direct relationship between bond prices and interest rates.
3. The price of short-term bonds fluctuates more than the price of long-term bonds for a given change in interest rates. (Assuming that coupon rate is the same for both)
4. The price of long-term bonds fluctuates more than the price of short-term bonds for a given change in interest rates. (Assuming that the coupon rate is the same for both)

Answer: I and IV only

Bond Duration

Consider a bond with a face value of $1,000, a coupon rate of 8%, a yield to maturity of 9%, and ten years to maturity. This bond's duration... Continue reading "Relationship between Interest Rates and Bond Prices" »

Assignment #3
Jedd Levin

1. The Minitab output clearly shows that the H: b=0 is accepted since the p-value is high. That is, the least square estimate 0.0109 for every unit of increment of the lagged return is not significantly different from a distribution with center about 0… or the alternative hypothesis b~= 0 is rejected. Basically, there is no statistical relationship between return at time t vs. The return at t-1.
2.  
   1. According to this line, what is the estimated average height of the children of parents whose height is 60 inches?

Avg child height =

26.4558+.61152*parent ht. At 60, child ht=26.2558+.6152*60

=63.1678”

What is the estimated height of the children of parents whose height is 72inches?

26.2558+0.6152*72

=70.5502”

How do the average... Continue reading "Sikandria port" »

Multiples consist of using the multiples of a company similar to yours to apply to your numbers and get an approximation of what yours is worth. It is not the most accurate in my opinion.

An example would be the EBITDA multiple, you multiply EBITDA by that figure obtained by dividing the value of the company you are comparing yourself to by its EBITDA.

This method is useful because although the estimated value of your company is not precise, with this method you can see the evolution over time.

250. The increase in provisions is not considered an outflow of cash, so it goes to the income statement.

– 150. The following are considered cash outflows

Add the cash paid instantly by the customer recorded in the cash flow statement as cash received... Continue reading "Valuation Methods and Cash Flow Analysis" »