Notes, summaries, assignments, exams, and problems for Mathematics

Statistics: Key Concepts and Methods

1. Statistics is a collection of methods for planning experiments, obtaining data, and then organizing, summarizing, presenting, analyzing, interpreting, and drawing conclusions.

2. Statistical methods consist of a series of procedures for managing, analyzing, and collecting qualitative and quantitative research data.

3. A population includes all objects of interest, whereas a sample is only a portion of the population.

Example: The population could be all students of a postgraduate program, and a representative sample of this population could be 400 students from different studies of the program.

Understanding Variables in Statistics

4. A variable is any characteristic, number, or quantity that can be measured... Continue reading "Key Concepts and Methods in Statistical Analysis" »

Unit 6: Costing and Production Systems

1. Production Systems

The two common cost accumulation systems are job order costing and process costing. The election to use one or the other of these systems depends primarily on the nature of the product and the manufacturing process by which it is created. Process production and job-order production are the extreme possibilities when considering the heterogeneity of products. The difference between order accounting and section accounting is the aim of the cost system, and the difference between process costing and job costing is the method to assign the cost to products.

1.1. Job Order Costing System

Job order costing suits the processes where it is necessary to assign costs to a specific amount of production... Continue reading "Costing and Production Systems: Job Order and Process Costing" »

Total Cost = w₁x₁ + w₂x₂ + … + w_nx_n

Isocost function:

x₂ = -w₁x₁/w₂ + tc/w₂ where the slope is: -w₁/w₂ ratio of relative factor prices with negative sign

Cost minimization mate: -w₁/w₂ = -MP₁/MP₂ (isoquant curve)

Cost minimization implies producing a certain amount of output (y > 0) with the lowest possible cost. As with the maximization of profits, the firm is getting the most out of the resources it is using.

What is the difference between cost minimization and profit maximization? Cost minimization is a necessary condition for the maximization of profits, but not the other way around. For example, if you bring costs down to zero then output and profits will be zero too, failing to maximize profits while minimizing costs. As before, when... Continue reading "Cost Minimization and Profit Maximization in Economics" »

Pocket money isn’t a controversial topic nowadays.

If there have been a lot of debates over pocket money.

Pocket money used to be a controversial topic.

T

Pocket money has always been a controversial topic.

T

The debate regarding pocket money nowadays is about how much money should be given.

If today’s debate rages about something entirely different.

The debate regarding pocket money nowadays isn’t about how much money should be given.

T

The debate regarding pocket money nowadays is about at what age money should be given.

If

Twelve-year-old will be able to use the new debit card.

A new debit card has just been launched for teenagers as young as 13.

Thirteen-year-olds won’t be able to use the credit card.

Teenagers over 13 will be able to use the... Continue reading "The Future of Pocket Money: Debit Cards and Financial Management" »

Key Statistical Concepts

Variables

Categorical (Qualitative) Variables: Represent characteristics or qualities. Examples include race and gender.

Quantitative Variables: Represent numerical values that differ in magnitude.

Scales of Measurement

• Nominal: Unordered categories.
• Ordinal: Ordered categories.
• Interval: Equal intervals between values.

Data Visualization

Frequency: Displays the possible values of a variable and the number of times each occurs.

Histogram: A bar graph of frequencies or percentages. Shapes can be bell-shaped, skewed, or bimodal.

Box Plot: Displays the distribution of data, including median, quartiles, and outliers.

Scatter Plot: Shows the relationship between two variables.

Distribution

• For symmetric distributions, the mean equals

CLARE FGF

1.- It was a long time since she had B carried

2.- Asked Bruno to address her C close

3.- A strong feeling of excitement D the average

4.- Having something to eat and B month compared

5.- Having something in common C growth, although

6.- She thought he might react B figure obtained

7.- Interested only in how she A researches put

8.- She discovers a way of D greater awareness

9.- Is in C line

RA:TS

10.- Nails A tend

9.- Record. D that

10.- Exception. H parti

11.- Sigh. F with

12.- Moment. A two

13.- To. C nowd HTTDFB

14.- Hugely. G it

15.- Strange. E when

14.- Country, Something

15.- Of such

WP

16.- Regularly B

17.- No longer C

18.- Tries to D

19.- Accepts C

20.- Is disa A

21.- Prefers D

22.- Is not A

23.- Now B

24.- Now D

25.- Likes to tell D

26.- Goes C -------

1) What is an Inverse Matrix and How Do You Calculate It?

A matrix A^-1 is called the inverse matrix of a matrix A (nxn) if AxA^-1= A^-1xA=E (where E is the identity unit matrix).

We calculate it by performing row operations on the augmented matrix (A | I) to transform it into (I | B). If this reduction is possible, then B=A^-1, which is the inverse matrix of A.

2) Define the Model of a Game

Games can be modeled in various forms:

• Tree Form Model (Game Tree): Represents the game as a sequence of decisions (moves) made by players.
• Normal Form Model: Represents the game using:
  • List of players
  • List of strategy spaces for each player
  • List of payoff functions (decision matrix) defining outcomes for each combination of strategies.
• Characteristic Function Form:

KEYS

1. You must be wondering why I haven’t phoned you.

2. The heavy rain prevented us from having the picnic we had planned.

3. Recently, there has been a rise in the number of people who study a degree.

4. It was a matter of minutes before the police came.

5. Can anyone come up with a solution to this problem?

6. Are you accusing me of not telling the truth about what happened?

7. I haven’t got round to phoning you, but I’ll do it soon.

8. Economists say that there is no doubt that the situation will get better.

9. It was my mother who/that got me interested in reading.

10. What is that’s causing you such a lot of confusion?

11. She made a very quick decision without giving enough thought to the matter.

12. It was a while until/ till/ before... Continue reading "Common English Phrases and Expressions for Language Learners" »