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Monday, 12 April 2021

Mean, Median and Mode

Who invented Median: Francis Galtons was the person to invent median.

Who invented Mode: Karl Pearson was the person to invent mode.

Who invented Mean: The term is first found in the mid-1690s in the writings of Edmund Halley.

What does Median mean?
The middle value of a range of values.

What does Mode mean?
The mode is the value that appears most frequently in a data set. A set of data may have one mode, more than one mode, or no mode at all.

What does Mean mean?
The mean (average) of a data set is found by adding all numbers in the data set and then dividing by the number of values in the set.

Why do we use Median?
The mean value of numerical data is without a doubt the most commonly used statistical measure. Sometimes the median is used as an alternative to the mean. ... Just like the mean value, the median also represents the location of a set of numerical data by means of a single number.

Why do we use Mode?
Mode is most useful as a measure of central tendency when examining categorical data, such as models of cars or flavors of soda, for which a mathematical average median value based on ordering can not be calculated.

Why do we use Mean?
The mean can be used to get an overall idea, or picture, of the data set. Mean is best used for a data set with numbers that are close together. The median can be used to get an idea of what values fall above the midpoint and what values fall below the midpoint.


A real life example of Median?
The number of students in a school, the amount of money an average citizen in a town earns, or the temperature for your vacation destination, are all numbers that are important in everyday life.


A real life example of Mode?
One of the factory owners lives in the town and his salary is in the millions of dollars. If you use a measure like the average to try to compare salaries in the town as a whole, the owner's income would severely throw off the numbers. This is where the measure of mode can be useful in the real world.

A real life example of Mean?
The mean is often used in research, academics and in sports. When you watch a baseball game and you see the player's batting average, that number represents the total number of hits divided by the number of times at bat. In other words, that number is the mean.


All of this information that I have gathered has come from Wikipedia.

Thursday, 8 April 2021

How to work out the volume

How to work out the volume?


What do we mean by volume?

the amount of space that a substance or object occupies or that is enclosed within a container.


How do we measure it?

In math, the volume is the amount of space in a certain 3D object. For example, a fish tank has 3 feet in length, 1 foot in width, and two feet in height. To find the volume, you multiply length times width times height, which is 3x1x2, which equals six. So the volume of the fish tank is 6 cubic feet.


Is there a conversion to liters?

A liter is a cubic decimetre, which is the volume of a cube 10 centimeters × 10 centimeters × 10 centimeters (1 L ≡ 1 dm3 ≡ 1000 cm3). Hence 1 L ≡ 0.001 m3 ≡ 1000 cm3 and 1 m3 (i.e. a cubic meter, which is the SI unit for volume) is exactly 1000 L.


The volume of a rectangle

To find the volume of a rectangle, multiply its 3 dimensions: length x width x height. The volume is expressed in cubic units.


The volume of a cylinder

A cylinder's volume is π r² h, and its surface area is 2π r h + 2π r²


The volume of a prism 

-Volume of a rectangular prism = (length x width x height) cubic units. V = (l x w x h) cubic units


The volume of a barrel

When used to denote a volume, one barrel is exactly 42 US gallons and is easily converted to any other unit of volume


The volume of a cone

The formula for the volume of a cone is V=1/3hπr²

M3

Cm3

Mm3

Some of this information that I have gathered has come from Wikipedia or google.


There is a pool.

The pool is 3m by 8m by 1.2m.

How much water does it take to fill the pool?

The pool is on a deck. How heavy is the pool.

3 x 8 x 1.2= 28.8m3

1L = 1Kg

28.8L= 28.8kg

I know that 1m3= 1000L

28.8 x 1000= 28,800L


There is a trailer of barrels

Each barrel is 1.5m high with a diameter or 0.75m

How much weight is on the trailer?

0.75/2 = 0.375

3.142 x 0.375 x 2= 2.3565

2.3565 x 1000= 2356.5

2356.5 x 6= 14139L