Saturday, September 22

Mean Median and Mode



What is the definition of mean median and mode?
Mean is a parameter of central tendency measure. The central tendency measure indicates the average value of data, where the term average is a generic term used to indicate a representative value that describes the general centre of data. Mean for raw data and for grouped data. For grouped data it is known as frequency distribution. Mean is the central value of the distribution in the sense that positive and negative deviations from the mean balance each other. It is a quantitative average.

Median is the central value of the distribution in the sense that the number of values less than the median is equal to the number of values greater than the median. So, median is a positional average. Median is the central value in the sense different from the arithmetic mean. In case of the arithmetic mean it is the numerical magnitude of the deviations that balances but, for the median it is the number of values greater than the median which balances against the number of values of less than the median.

Mode is defined as the value of the variable which occurs most frequently. Mode is for both raw data and grouped data. In raw data the most frequently occurring observation is the mode that is data with highest frequency is mode. If there is more than one data with highest frequency then each of them is a mode. Thus we have unimodal means single mode, bimodal means two mode and trimodal means three modes data sets. In grouped data mode is that value of (x) for which the frequency is maximum. If the values of (x) are grouped into the classes such that they are uniformly distributed within any class and we have a frequency distribution than we calculate maximum frequency by using formula.

What is the mean median mode in math?
Now we discuss about what does mean median mode mean in math. There are some formulas in math for mean median and mode.
For raw data mean= [∑x/n], x is refers to value of observation, n is the number of observations.
For grouped data mean= [∑fx/∑f]
Median= [(n+1)/2]
Mode=L+ [f0-f1/2f0-f1-f2]*h, L is lower limit, f0 is largest frequency, f1 is preceding frequency, f2 is next frequency and h is width.
Now, How to find the mean median and mode. Suppose we have given some problem then to find mean median and mode we can use above formula, by using formulas we can get the results.

Thursday, September 13

Understanding the box and whisker plot



Box and whisker plot definition:
The basic assumption in statistics is that a set of data has a central tendency. That means the number of the data are distributed around some central value. The box of the box-whisker plot takes care of the middle half observations of the data. So we can define the box-whisker plot as a diagram that represents the tendency of data to centre on the median.

Box and whisker plot examples:
The following pictures show box and whisker plot of various data sets.

Shown above is a box-whisker plot of weight in pounds of players.

Shown below is a box- whisker plot of the length of fish in a particular lake:

From the plot we can see that the median length is 12 cm. The smallest fish has a length of 5 cm, the longest fish is 20 cm long. Most of the fishes lie between 8.5 to 14 cm in length, where 8.5 is the lower quartile and 14 cm is the upper quartile.

How to make a box and whisker plot:
Step 1: Arrange the data in ascending order from the lowest to highest value.

Step 2: Find the median of the data. For a data of n observations, median = ((n+1)/2)th observation if n is even and if n is odd then median = average of (n/2)th and ((n+2)/2)th observation. So if number of observations = 11 then (11+1)/2 = 12/2 = 6th observation is the median. But if number of observations is 14, then average of 14/2 = 7th and (14+2)/2 = 16/2 = 8th observation would be the median.

Step 3: The median that we found above has now divided the data into two halves. Now to further divide each of the half into two quarters, we need the 1st and the 3rd quartile values. Suppose the median is the mth observation. Then the middle value between the 1st and the mth observation would be the 1st quartile and the middle value between the mth and the last observation would be the 3rd quartile. They are denoted by Q1 and Q3.

Step 4: Now  you have these three values, Q1, M (= median) and Q3. We also have the lowest and the highest observation, X1 and Xn. So we now have 5 points. We make a number line using suitable scale and mark these 5 points and draw a box around the Q1 to Q3. That is our box and whisker plot.

Monday, September 10

Step by step math solution



Mathematics is used throughout the world and it is an essential tool in many fields like natural science, engineering, medicine, and the social sciences. "Mathematics" is the Greek word its gives the meaning of learning, study, science, and additionally came to have the narrower and more technical meaning "mathematical study", even in Classical times.

Step by Step Math Solutions - Method to Solve:

There are many formulae abounded for solving math problem step by step One of the most important formula is P.E.M.D.A.S. It is nothing but the operations done in the problems solving in math. They are

  • Parenthesis
  • Exponents
  • Multiplication
  • Division
  • Addition
  • Subtraction

Step 1: First perform the operations inside a parenthesis.
Step 2: Now solve the exponents
Step 3: Then multiplication and division is done from left to right
Step 4: Then addition and subtraction is done from left to right

Step by Step Math Solutions - Example Problems:

Step by step math - Problem 1:

Solve the equation step by step

X + 6 = 8

Solution:

It is one step equation

Subtract 6 on both sides

X + ( 6 - 6 ) = (8 - 6)

X = 2

Step by step math - Problem 2:

Solve the equation step by step

4x + 2=18

Solution:

Subtract 2 on both sides

4x + (2 - 2) = 18 - 2

4x = 16

Divide by 4 on both sides

`(4x)/4` = `16/4`

X = 4

Step by step math - Problem 3:

Find the value of x step by step

6x - 8 = 4 x -10

Solution:

Subtract 4x  from both sides of the equation

2x - 8 = - 6

Add 6 to both sides of the equation

2x = 2

Divide both sides by 2:

x = 1

The answer is x =  1

Step by Step Math Solutions - Probability Problems:

Step by step math - Problem 1:

A fair coin is tossed two times. What is the probability of getting at least one heads.

Solution:

Let A = be the event of getting at least two heads

Let S = Sample Space which refers to the total number of probable outcomes.

S = (HH, HT, TH, TT) =4

A = (HT, TH) =2

P (A) = `2/4` = `1/2`

The probability is `1/2` .

Step by step math - Problem 2:

Consider a die is rolled; calculate the probability of in receipt of odd numbers?

Solution:

There are six different outcomes 1,3,5,7,9,10,12,14,16,17,18

n (A) = 6, total number of odd numbers occur 6.

n (S) = 11, total number of outcomes is 11.

Probability of the event A happen = P (A) = n (A) / n(S) = `5 / 11` = 0.45.

Probability of the event A does not happen = P (A') = 1 – P (A) = 1 - 0.45 = 0.55.

Thursday, September 6

Circle Division



A circle is a closed curve. The points on the circle are equidistant from the center of the circle. A circle creates 2 regions, the interior of the circle is one region and the exterior is another region.

A circle can be divided into equal or unequal parts. The division can be accomplished by straight lines or curved lines. With every nth line the circle gets divided into n+1 parts, meaning with one line circle can be divided into 2 parts, with nth line circle can be divided into n+1 parts assuming that the lines do not intersect.

Circle Division Term in Maths:

A circle division can be accomplished by using a straight line or a curved line. As we are not considering the area calculation for this discussion, let us restrict ourselves to straight lines for the purposes of this study.

The straight line that joins a point on the circumference of the circle to another point on the circumference of the same circle is called a chord. A chord divides the circle into 2 parts.

Consider several chords on the circle and suppose some or all of the chords intersect. Then it is found that the number of area regions that the chords cut the circle into is always more than the number of chords passing through the circle.

Here is an example

The above is popularly known as the cake cutting example.

In the first picture, one chord divides the circle into 2 parts.in the second picture, two chords divide the circle into 4 parts, in the third three chords divide the circle into 3 parts and the forth diagram 4 chords divide the circle into 11 parts.

Here you see that the first cut creates 1 new region (1+1)

The second cut creates 2 new regions (2+2)

The third cut creates 3 new regions (4+3) and the 4th cut creates 4 new regions (7+4)

This is mathematically represented as

F (n) = n + f (n-1)

Conclusion for Circle Division:

Circle division is an important study in geometry that gives several clues for practical applications. There are several theorems and postulates that delve deeper into circle division and provide new insights into this area of study.

Tuesday, September 4

Frequency and Frequency Table



Frequency table, it comes under the category of statistics. First we see about frequency. The frequency of a given table or data is that how many times the value occurs in table or data. For example, suppose in a class five students are score sixty marks in mathematics then the score of sixty is said to have frequency of five. Frequency means range of values also and the frequency of any data is denoted as (ƒ).

What is a frequency table?
A frequency table contains sets of collected data values. The arrangement is such that the magnitude of collected data values is in ascending order along with the corresponding frequencies. Now frequency table definition in other way is that it is a list of quantity in ascending order and list shows the numbers how many times each value occurs.

How to make a frequency table?
Here we understand the procedure of preparing A frequency table. For this we follow some steps. In step one; we make a table with three columns. In these three columns, first columns shows the marks and marks are arranged in ascending order means start from the lowest value. The second column shows tally marks. It means put corresponding tally in front of marks. When all values listed then make horizontal lines for all the values. Third column shows frequency, count the value of frequency for each mark and write in third column. Finally the frequency table is constructed.

The frequency table is different for different types of problems. Sometimes in problems range values is given with no of students and cumulative numbers. When we make frequency table for this type of problem then in first column we write range value in ascending order. In second column we write number of student which comes under the corresponding range. In third column we write cumulative numbers then we solve the problem.
Always i find probability distributions is very hard for me. If you do feel the same watch out for my coming posts.

How to do a frequency table?
We start with simple example. Suppose we have a frequency table with two columns. In first column marks(20-30, 30-40,40-50,50-60, 60-70) is given and in second column frequency(2,4,3,5,7) is given. Frequency column represent the number of students who scored marks in particular range of frequency. We have to calculate the number of student who gets fifty plus marks. Fifty plus marks comes in 50-60 and 60-70 range and their corresponding number of student is 5 and 7. So the answer is 12 students.

Wednesday, August 29

Integral properties and definition



In this article first we define Integration, in mathematics it is an important concept. Its inverse definition is also equally important. Integration is one of the main operations from two basic operations of calculus. In simple form we can define that integration means to calculate area. Now we define mathematically, suppose we have a given function (f) with real variable (x) over an interval [a, b] for a given real line, then we expressed this function as ∫f(x) dx. Integration means calculation of area of the region in XY-plane, which is bounded by the graph of function (x). Area above from the X-axis adds the total value and area below the X-axis subtracts from the total value.

The term integrals also known as antiderivatives. Suppose we have a given function is (F) and derivative of this function is (f). In this case it is known as indefinite integral and can be expressed as ∫f(x) dx. The notion of antiderivative are basic tools of calculus. It has many applications in science and field of engineering. Integral is an infinite sum of rectangles of infinite width. Integral is based on limiting procedure of area. Line integral means function with two or three variables where closed interval are replaced by any curve. Curve may be made in any plane or space. In surface integral in place of plane a short piece of surface is used.

There are various integral properties; integral properties are for the definite notion of antiderivative based on the certain theorems. First theorem is, suppose M(x) and N(x) are two defined functions. They are also continuous function in interval [a, b], then we have linearity property for the notion of antiderivative which can be expressed as
∫ [M(x) +N(x)] dx= ∫M(x) dx + ∫N(x) dx
∫a. M(x) dx= a∫M(x) dx. a is an arbitrary constant and we carry out the constant term from the function.
Second theorem is, suppose function f(x) is defined which is continuous in closed interval [a, b], then we have some special property of integral such as…
∫f(x) dx= 0, when limit are same.
∫f(x) dx= ∫f(x) dx+∫f(x) dx, when limits are divided between interval s like a to c and c to b.
∫f(x) dx= -∫f(x) dx, when upper limit becomes lower limit and lower limit becomes upper limit.

There are many integral types such as definite integral in which function is continuous and define in a closed interval. Other types are indefinite integrals, surface integrals, double integral known as Green’s theorem, triple integrals known as Gauss divergence theorem and line integrals

Monday, August 27

Graphing Trig functions




Sine graph equation:
The general form of a sine function is like this:
Y = sin x.
As we already know, sine is a periodic function. The period of a sine function is 2 pi. That means each value repeats itself after an interval of 2𝛑 on the x axis. The range of the sin function is from -1 to 1. So the value of sin x would not exceed 1 and would not go below -1 at any point. To be able to plot the graph of the function, let us make a table of values of the sine function.

The graph of the above table would look like a wave.

Cosine graph equation:
Just like the sine function, the cosine function is also periodic. The parent cosine function would be like this:
y = cos x
Similar to the sine function, the range of the cosine function is also from -1 to 1. The period of the cosine function is also 2𝛑. That means that the value of the function repeats itself after an interval of 2𝛑. To be able to plot the cosine function now let us make a table of values of cos.

The graph of the function would look like this:

How to graph tangent functions?

The tangent function is also a periodic function. However the period of the tangent function is 𝛑. That means the values repeat itself after an interval of ?? on the x axis. The range of the tangent function is –inf to inf. That means that the tangent function can have any real number value. Just like how we did for the sine and the cosine functions, for plotting the tangent function also we shall make a table of values.