Notes, abstracts, papers, exams and problems of Mathematics

Statistical Hypothesis Testing

1. Statistical Hypothesis

A statistical hypothesis is an assertion about a characteristic or parameter of a population. It's used to perform analysis and can be either rejected or accepted based on the provided information. There are two types of hypotheses:

• Null Hypothesis (H₀): Represents the status quo or the default assumption.
• Alternative Hypothesis (H₁): Represents the claim or the hypothesis we want to test.

Both H₀ and H₁ can be simple (if the parameter has only one value) or compound (if the parameter can take multiple values).

2. Significance Level (α)

The significance level is the probability of making a Type I error (rejecting H₀ when it's actually true). It represents the level of risk we're willing to... Continue reading "Statistical Hypothesis Testing: Errors, Power, and Inference" »

Phases of a File Report

Depending on the activity or inactivity of files, a file in healthcare (HC) can be categorized into three stages:

• Active Archive
• Passive File
• Historical Archive

• Active file: This is one that meets the active healthcare compliance (HHCC), i.e., records subject to continued use and consultation.
• Archive candidate: This is one that meets the inactive HHCC, i.e., one that you have to transfer from active files when a query in a time interval of 3 to 5 years is nil. These documents remain here until disposal or transfer to the historical archive.
• Historical Archive: This is where documentation is transferred from the passive file after 10 years without being consulted. These documents are kept permanently because they were not

Checks: A Comprehensive Overview

What is a Check?

A check is a document instructing a bank (the drawee) to pay a specific amount of money to the check holder (the payee) from the account of the person who wrote the check (the drawer).

Parties Involved

• Drawer: The person who writes and signs the check, authorizing the payment.
• Drawee: The bank or financial institution where the drawer has an account.
• Payee/Holder: The person or entity to whom the check is made payable.
• Guarantor: A person who guarantees payment if the drawer's account has insufficient funds.
• Endorser: The payee who signs the back of the check to transfer ownership.
• Endorsee: The person to whom the check is endorsed.

Types of Checks

Forms of Writing

• Bearer: Payable to the person holding

Critical Path Method (CPM) vs. PERT

HL (time to completion may be delayed without affecting the beginning of another and final term), HM (the worst case of free float.) Critical path: the path of longer duration and is defined by the sequence of activities that mark critical events in the network. These activities are styled with a double arrow. An activity is critical when it has no slack time, and an event is critical when its TE (earliest time) and TL (latest time) are equal. We must pay critical attention to these routes, as any delay may affect the entire project. Beginning and ending events are critical.

PERT (Program Evaluation Review Technique): It is a probabilistic system that assigns each possible activity three durations: pessimistic,... Continue reading "Critical Path Method (CPM) vs. Program Evaluation Review Technique (PERT)" »

Exercise 1: Calculating Monthly Interest Rate

A person invested $12,000 in an institution and received $13,008.00 after seven months. What is the equivalent monthly interest rate that the investor earned?

Solution:

• Initial Capital (C) = $12,000
• Time (n) = 7 months
• Future Value (FV) = $13,008.00

Using the formula: FV / C = (1 + i * n)

13,008.00 / 12,000.00 = (1 + i * 7)

1. 0840 = 1 + 7i

2. 0840 = 7i

i = 0.0840 / 7

i = 0.012 or 1.2% per month

Exercise 2: Equivalent Financial Return

An investment of $15,000 is made for a period of three months at a simple interest rate of 26% per annum. What amount must be invested for two months at a linear rate of 18% per year to achieve the same financial return?

Solution:

Investment 1:

• C = $15,000
• n = 3 months
• i (annual)

Direct Methods

1a) Gauss Elimination Method

The Gauss Elimination method consists of converting a matrix into an equivalent matrix with zeros below the main diagonal of A. The first equation will have n variables, the second n-1, and so on until the final equation, which will have only one variable. Once the zeros are achieved, the values of the variables are found by starting with the last variable and substituting back up to the first. This solves the system.

1b) Gauss-Jordan Method

The Gauss-Jordan method consists of obtaining a diagonal matrix instead of just an upper triangular matrix. Variables are obtained directly from the resulting system, without substitutions. This saving in the final step comes at the cost of slightly increasing the... Continue reading "Direct and Indirect Methods: Gauss and Jacobi" »

Parties Involved in a Bill of Exchange

The issuance and circulation of a bill of exchange involves the following parties:

• The Drawer: The creditor who issues the bill of exchange, instructing the debtor to pay.
• The Drawee: The debtor who is obligated to pay the bill of exchange at maturity. The drawee may accept or reject the payment order. If accepted, the drawee becomes the acceptor.
• The Payee/Holder/Beneficiary: The person who holds the bill of exchange and is entitled to receive payment.

Form of Bills of Exchange

A bill of exchange must be issued on official forms or stamped paper issued by the State. The amount should be proportional to the value stated on the bill. Improper formatting may cause difficulties in pursuing action against the debtor... Continue reading "Understanding Bills of Exchange: Parties, Form, and Accounting" »

Time Study in Work Measurement

The study of time as one of the major work measurement techniques was formalized by Taylor.

Technical Insolvency

A firm is in a state of technical insolvency when the economic profit generated by its assets is not sufficient to meet the interest on its debts.

Quota Sampling

Quota sampling falls under the category of non-probability sampling.

Commercial Experimentation Technique

Analysis of Variance

The technique used in most commercial experimentation is Analysis of Variance.

Strategic Behavior and Social Groups

The set of shared values of a social group determines your preference for a particular type of strategic behavior.

Investment Risk

If a certain level of risk exists between two alternative investments, preference... Continue reading "Time Study, Sampling, and Business Management Concepts" »

Practice 4: Salaries, Overtime, SSO, PHL

Basic Salary

• = (Additional Table at $[$D$24] * Time Worked)

Total Overtime

• Fx = IF(logical test = E10 [Overtime] > 40)
• True-Value: E10 - 40
• False-value: 0

Triple Overtime

• Fx = IF Function
• Logic Test: Total Overtime [G10 > 8]
• True-Value: G10 - 8
• False-value: 0

Payment of Extra Time Triple

• Triple Overtime (H10) * Pay Per Hour (D24) * 3

Double Overtime

• = G10 (Total Overtime) - H10 (Triple Overtime)

Payment of Extra Time Double

• = J10 (Double Extra Time) * D24 (Pay per hour) * 2

Compulsory Social Security (SSO)

• = (F10 [Basic Salary] + I10 [Payment of Triple Overtime] + K10 [Payment of Double Overtime]) * 5%

Housing Policy Act (HPL)

• = (F10 [Basic Salary] + I10 [Payment of Triple Overtime] + K10 [Payment of Double Overtime]