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

Sampling Stage

Sample Size:

• Depends on population size
• The type of sample
• Feature (parameter) of the population that is analyzed
• The maximum permissible error in the estimation of the parameters

The Form: The information collected can be classified as:

• Acts or behaviors that can be compared
• Information: analyzes the degree of respondents' knowledge on specific topics
• Opinions or Judgments: such as perceived service quality
• Attitudes or predispositions of mind: We are looking for what is thought in relation to something
• Motives or explanations for specific behaviors: the question is, why certain views or acts?
• Possible future behavior: it may ask whether or not to consume a prepared product.

Concept and Structure of Questionnaires

The questionnaire is a way... Continue reading "Effective Questionnaire Design for Market Research" »

Food and Nutrition

Food is the act of providing sustenance to the human body, while nutrition encompasses the physiological processes by which the body receives, transforms, and utilizes the chemical components in food.

Inherited Diseases

• Hemophilia
• Huntington's disease
• Cystic fibrosis
• Color blindness
• Phenylketonuria

Measures of Dispersion

Measures of dispersion indicate how close the data are to the average.

Vaccines

Vaccines are preparations containing killed or attenuated microorganisms. They are introduced into our bodies to produce antibodies that kill the organism, providing immunity.

Common Pathogens

Pathogens such as bacteria and fungi are the most common causes of infectious diseases.

Health and Disease

Health is a state of complete physical, mental,... Continue reading "Key Concepts in Health, Nutrition, and Statistics" »

IT Project Management and Departmental Structure

Resource Management in IT Projects

Resource management projects often involve:

• IT professionals (informaticians).
• SAP systems, often developed in Germany.
• Project integrity, focusing on achieving target costs and timelines.

Evolving Role of the IT Department

The aim is for the Information Technology (IT) department to become more self-sufficient, reducing its reliance on other functions like accounting or human resources.

Within the IT department, there are project managers, analysts, and programmers. Each functional area typically has a manager, and similarly, the IT department should also have its own manager.

IT Department as a Cost Center

While most functions within an organization generate revenue,... Continue reading "Optimizing IT Operations: Systems, Costs, and Users" »

Exercise 01: Call Center Call Time

Suppose that the time needed for customer service calls in a telephone call center follows a Normal distribution with a mean of 8 minutes and a standard deviation of 2 minutes.

1. What is the probability that a call lasts less than five minutes?
2. What is the probability that a call lasts more than 9.5 minutes?
3. What is the probability that a call lasts between 7 and 10 minutes?
4. 75% of calls require at least how long for service?

Exercise 02: Rabbit Weight Classification

The distribution of the weights of rabbits raised on a farm may well be represented by a Normal distribution with a mean of 5 kg and a standard deviation of 0.9 kg. An abattoir buys 5000 rabbits and intends to classify them according to weight as follows:... Continue reading "Statistics Exercises: Normal Distribution" »

Working Papers

These are the documents in which the auditor records the data and information obtained during their review, as well as the results of the tests performed.

Summary Warrant

A sample of major accounts that are an item.

Worksheet

This is the card that shows the groups or items that comprise the financial statements.

Decree of Detail

The items that comprise an account balance of a major account or any other account.

Certificates of Verification

The work performed to verify the correctness of an item or transaction.

Situations for Audit Work Plan

• Ensure that the service is clearly controlled.
• Be fully aware of what is being offered.

Conditions to Perform the Audit

• Maintain independence of mind regarding the specific client.
• Possess the ability to

Sampling Process and Principles

To ensure a sample accurately represents the population under investigation, its size and the methodology used must adhere to specific principles.

Core Sampling Concepts

Population (Universe)

The population, or universe, is defined as the complete set of elements existing within a specific space and time, all of which are affected by the same problem under study, and from which information is desired.

Sample

A sample is a representative fraction of the population. From the sample, we can infer or estimate the characteristics of the entire population.

Sampling

Sampling is the procedure for selecting a subset of elements (the sample) from a larger group (the population) in order to make inferences about the population.... Continue reading "Statistical Sampling: Core Concepts and Essential Elements" »

Types of Auditor Opinions

Unqualified Opinion

An unqualified opinion is issued when:

• The audit was performed without limitations in scope and in accordance with the National Technical Standards (NTA).
• The annual accounts have been prepared in accordance with accounting rules and Generally Accepted Accounting Principles (GAAP), consistent with prior years.
• The information, including supporting documentation, is sufficient for adequate comprehension.
• The financial statements, taken as a whole, fairly represent the company's business in accordance with the information available to the auditor.

Qualified Opinion

A qualified opinion is issued when the auditor concludes that there are significant circumstances that prevent the annual accounts from presenting... Continue reading "Auditor's Opinions: Types and Implications" »

• Rating Alphabetical: Documents are classified based on the name of the person or the reason for the company shown in the document.
• Geographical Breakdown: Documents are classified by place of residence of the person or entity, as the province-city-street and finally the name.
• Classification of Materials: Documents are grouped according to the topic at hand, understood as a common feature field.
• Alphabetical Materials as Logical Categories:

a) Number: Each field is assigned a number, and each subdivision a number.
b) Alphanumeric: Each field is assigned a letter or number, and subdivisions another letter or number that is added to the first component.

• Rating Chronological: Ordering progressively, by date of entry or maturity.
• Decimal Classification:

Adverbs

An adverb is a word that acts as the core of an adverbial phrase. It modifies a verb, an adjective, or another adverb.

Classification of Adverbs

• Place: out there, here, up close, in front, within, above, across, away, etc.
• Time: now, before, even yesterday, after, today, then, tomorrow, never, soon, always, yet, etc.
• Quantity: something, pretty, almost, too much, well, nothing, just, so, so much.
• Manner: agile, well, good, bad, fair, bravely, and so on.
• Order: before, after, later, first, respectively, and so on.
• Affirmation: true, certainly, of course, actually, probably, yes, indeed, and so on.
• Negation: never, no, never, no, etc.
• Doubt: perhaps, possibly, probably, maybe, perhaps, etc.
• Question: how, when, where.
• Relative: how, when, where.

Prepositions

A... Continue reading "Adverbs, Prepositions, Verbs, Pronouns & Conjunctions" »

Correlation Diagram: Analyzing Variable Relationships

Understanding Correlation Diagrams

A correlation diagram is a powerful tool that studies the relationship between two variables. It is used to understand if two variables are linked and to what extent they are.

Types of Variable Relationships

The relationship between variables can be:

• A direct cause-and-effect relationship.
• Multiple causes leading to one effect, or one cause leading to several effects.

It is represented by a graph with two axes, where the values of each variable are plotted on a respective axis. For the chart to be reliable, it requires at least 20 pairs of data. Once a sufficient number of points are plotted, you can determine whether a relationship exists between the variables.... Continue reading "Quality Management Tools: Correlation, Control Charts, and Poka-Yoke" »