Types of Statistics

Let me explain about the types of statistics,
For many people, statistics means numbers—numerical facts, figures, or information. Reports of industry production, baseball batting averages, government deficits, and so forth, are often called statistics. To be precise, these numbers are descriptive statistics because they are numerical data that describe phenomena. Descriptive statistics are as simple as the number of children in each family along a city block or as complex as the annual report released from the U.S. Treasury Department.
Consider two ways of representing descriptive statistics: numerical and pictorial.

Numerical statistics :

Numerical statistics are numbers, but clearly, some numbers are more meaningful than others. For example, if you are offered a purchase price of $1 for an automobile on the condition that you also buy a second automobile, the price of the second automobile would be a major consideration (its price could be $1,000,000 or only $1,000), and thus, the average—or mean—of the two prices would be the important statistic.

Pictorial statistics :

Taking numerical data and presenting it in pictures or graphs is what is known as pictorial statistics. Showing data in the form of a graphic can make complex and confusing information appear more simple and straightforward.
Hope the above explanation was useful to you.

Graphing Linear Inequalities in Two Variables

Let me explain about Graphing Linear Inequalities in Two Variables,
A linear inequality in the two variables x and y looks like

where a, b, and c are constants.
A solution to an inequality is any pair of numbers x and y that satisfy the inequality.
The rules for finding the solution set of a linear inequality are much the same as those for finding the solution to a linear equation.

1. Add or subtract the same expression to both sides.
2. Multiply or divide both sides by the same nonzero quantity; if that quantity is negative, then the inequality must be reversed.

Hope the above explanation helped you.

Explain Mathematical induction

Let us study about mathematical induction,
Mathematical induction, or proof by induction, is a method of mathematical proof typically used to establish that a given statement is true for all natural numbers. It can also be used in more general settings as will be described below. An induction variant is used in computer science to prove that expressions which can be evaluated are equivalent, and this is known as structural induction.
The simplest and most common form of mathematical induction proves that a statement holds for all natural numbers n and consists of two steps:

Showing that the statement holds when n = 0.
Showing that if the statement holds for n = m, then the same statement also holds for n = m + 1.

To understand why the two steps are in fact sufficient, it is helpful to think of the domino effect: if you have a long row of dominos standing on end and you can be sure that
The first domino will fall.
Whenever a domino falls, its next neighbor will also fall.
then you can conclude that all dominos will fall.
Hope the above explanation was helpful.

Triangle Inequalities: Sides and Angles

Let us learn what are Triangle inequalities,
You have just seen that if a triangle has equal sides, the angles opposite these sides are equal, and if a triangle has equal angles, the sides opposite these angles are equal. There are two important theorems involving unequal sides and unequal angles in triangles. They are:

Theorem: If two sides of a triangle are unequal, then the measures of the angles opposite these sides are unequal, and the greater angle is opposite the greater side.

Theorem: If two angles of a triangle are unequal, then the measures of the sides opposite these angles are also unequal, and the longer side is opposite the greater angle.

Example : Figure 1 shows a triangle with angles of different measures. List the sides of this triangle in order from least to greatest.
Figure : List the sides of this triangle in increasing order.

Because 30° < 50° < 100°, then RS < QR < QS.

Coordinates of a Point in Space

Let us learn about Coordinates of a Point in Space,
Having chosen a fixed coordinate system in the
space, consisting of coordinate axes, coordinate
planes and the origin, we now explain, as to how,
given a point in the space, we associate with it three coordinates (x,y,z) and conversely, given a triplet of three numbers (x, y, z), how, we locate a point in the space.
Given a point P in space, we drop a
perpendicular PM on the XY-plane with M as the
foot of this perpendicular (Fig.). Then, from the point M, we draw a perpendicular
ML to the x-axis, meeting it at L. Let OL be x, LM be y and MP be z. Then x,y and z
are called the x, y and z coordinates, respectively, of the point P in the space. In
Fig, we may note that the point P (x, y, z) lies in the octant XOYZ and so all x, y,
z are positive. If P was in any other octant, the signs of x, y and z would change accordingly. Thus, to each point P in the space there corresponds an ordered triplet
(x, y, z) of real numbers.
Hope the above explanation helped you, now let me give you some examples on Coordinates of a Point in Space.

Coordinate Axes and Coordinate Planes in Three Dimensional Space

Let us study about Coordinate Axes and Coordinate Planes in Three Dimensional Space.
Consider three planes intersecting at a point O such that these three planes are mutually perpendicular to each other (Fig). These
three planes intersect along the lines X′OX, Y′OY
and Z′OZ, called the x, y and z-axes, respectively.
We may note that these lines are mutually
perpendicular to each other.

These lines constitute the rectangular coordinate system. The planes XOY, YOZ and ZOX, called, respectively the XY-plane, YZ-plane and the ZX-plane, are known as the three coordinate planes. We take the XOY plane as the plane of the paper and the line Z′OZ as perpendicular to the plane XOY. If the plane of the paper is considered
as horizontal, then the line Z′OZ will be vertical. The distances measured from
XY-plane upwards in the direction of OZ are taken as positive and those measured
downwards in the direction of OZ′ are taken as negative. Similarly, the distance
measured to the right of ZX-plane along OY are taken as positive, to the left of
ZX-plane and along OY′ as negative, in front of the YZ-plane along OX as positive
and to the back of it along OX′ as negative. The point O is called the origin of the
coordinate system. The three coordinate planes divide the space into eight parts known
as octants. These octants could be named as XOYZ, X′OYZ, X′OY′Z, XOY′Z,
XOYZ′, X′OYZ′, X′OY′Z′ and XOY′Z′. and denoted by I, II, III, ..., VIII , respectively.
Hope the above explanation helped you, now let me explain you about Navigational Coordinates.

Set builder method

Let me explain you about Set builder method, one of the method of representing a set.
In set-builder form, all the elements of a set possess a single common property
which is not possessed by any element outside the set. For example, in the set
{a, e, i, o, u}, all the elements possess a common property, namely, each of them
is a vowel in the English alphabet, and no other letter possess this property. Denoting
this set by V, we write
V = {x : x is a vowel in English alphabet}

It may be observed that we describe the element of the set by using a symbol x
(any other symbol like the letters y, z, etc. could be used) which is followed by a colon
“ : ”. After the sign of colon, we write the characteristic property possessed by the
elements of the set and then enclose the whole description within braces. The above
description of the set V is read as “the set of all x such that x is a vowel of the English
alphabet”. In this description the braces stand for “the set of all”, the colon stands for
“such that”. For example, the set
A = {x : x is a natural number and 3 < x < 10} is read as “the set of all x such that x is a natural number and x lies between 3 and 10. Hence, the numbers 4, 5, 6, 7, 8 and 9 are the elements of the set A. If we denote the sets described in (a), (b) and (c) above in roster form by A, B, C, respectively, then A, B, C can also be represented in set-builder form as follows: A= {x : x is a natural number which divides 42} B= {y : y is a vowel in the English alphabet} C= {z : z is an odd natural number} Hope the above explanation helped you, now let me give you some examples on Set builder method.