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

Descriptive and Inferential Statistics

Descriptive Statistics

Descriptive statistics involve organizing, summarizing, and presenting data. This can include using:

• Graphs
• Frequencies
• Tables

Inferential Statistics

Inferential statistics involve drawing conclusions from data.

Example: Fitness Center Data Analysis

A fitness center wants to know the average time clients exercise each week.

Key Concepts:

• Population: All clients in the fitness center
• Sample: A group of clients from the fitness center
• Parameter: Population mean amount of time clients exercise each week
• Statistic: Sample mean amount of time clients exercise each week
• Variable (X): The amount of time one client exercises in the center each week
• Data: Values for X (e.g., 4 hours, 6 hours, 10 hours)

Important

Business Documents

Commercial documents, also called "proof," constitute the evidence of any business operation conducted by a company. Thus, each proof tests a type of transaction. It is known that any operation involves at least two parts. For each of them, it will have a different meaning (as discussed later: buyer or seller, debtor or creditor, or collector payer, etc.).

Small-Scale vs. Large-Scale Risk Aversion

The core idea is to understand the differences between how small and large changes in wealth affect risky gambles.

Diminishing marginal utility (risk aversion) primarily applies to large-scale gambles. This is because the utility function is sufficiently concave over lifetime changes in wealth. This concavity results in a higher utility for taking a certain outcome than for taking a gamble, even if the gamble has a higher expected return.

However, for small-scale gambles, the utility function is locally linear, yielding almost risk-neutral behavior. For wealthy individuals, the utility function is very weakly concave, leading to an asymptotically linear curvature. Thus, diminishing marginal utility cannot...

Which of the following is most likely an issuer bonds: HEDGE FUND

A bond issued by a city would most likely be classified as a: NON-SOVEREIGN GOVERNMENT BOND

A fixed-income security issued with a maturity at issuance of nine months is most likely classified: MMSECURITY

The price of a bond issued in the US by a British company and denominated in US dollars is most likely: CHANGE AS US INTEREST RATES CHANGE

Interbank offered rates are best described as the rates at which major banks can: BORROW UNSECURED FUNDS

A company issues floating-rates bonds. The coupon rates is expressed as the three-month Libor plus a spread. The coupon payments are most likely: LIBOR INCREASES

A 10-year bond was issued four years ago. The bond is denominated in US dollars,

Selecting Samples

A simple random sample of size n from a finite population of size N is a sample selected such that each possible sample of size n has the same probability of being selected.

A random sample of size n from an infinite population is a sample selected such that the following conditions are satisfied.

Point Estimation

By making the preceding computations, we perform the statistical procedure called point estimation. We refer to the sample mean x as the point estimator of the population mean m, the sample standard deviation s as the point estimator of the population standard deviation s, and the sample proportion p as the point estimator of the population proportion p. The numerical value obtained for x, s, or p is called the point...

What is a One-Way Function?

A one-way function is a function that is easy to compute in one direction but difficult to compute in the reverse. For example, given an input, a hash is easy to compute. However, given the output, it is extremely difficult (time-consuming) to determine the input.

What is a Trapdoor Function?

A trapdoor function is like a one-way function; however, a trapdoor function can reverse the one-way function if the trapdoor is known. For example, finding the two prime divisors of 6,895,601 is difficult. However, if you know that 1,931 is one of the numbers, it will be easy to divide 6,895,601 by 1,931 to determine the answer. In this case, 1,931 is the trapdoor.

What Makes RSA Difficult to Break?

The large number factorization...

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.

Descriptive Statistics

Classification and description of a dataset.

Statistical Inference

Interpreting results using descriptive techniques for decision-making.

Statistic

A numerical summary or descriptive feature of a total sample of research.

Frequency Polygon

A line graph usually plotted on a frequency histogram.

Experiment

A controlled procedure carried out to determine, demonstrate, or test a hypothesis; a process that yields an outcome.

Median

The midpoint of a data set.

Probability

Measures or quantitatively determines the possibility that an event occurs.

Objective Probability

Probability obtained through numerical calculations or empirical observations.

Classic Approach

Assumes that all events are equally likely to occur.

Event

A possible outcome or...

International Accounting Standard No. 10

Events Occurring After the Balance Sheet Date

Objective

The objective of this Standard is to prescribe:

1. when an entity shall adjust its financial statements for events after the balance sheet date and
2. the disclosures that an entity should give about the date on which the financial statements were authorized for issue and about events after the balance sheet date.

The Standard also requires the entity that does not prepare its financial statements under the assumption of going concern, if the events after the balance sheet date indicate that this hypothesis of continuity is not appropriate.

Scope

This Standard is applicable in the accounting and disclosures related to events after the balance sheet date.

The events