Actually, I'll just get the calculator out for this part. I could do it by hand, but we'll save some time over here. So we have 23 plus 29 plus 20 plus 32 plus 23 plus 21 plus 33 plus So the sum of all the numbers is And then we want to divide by 8. So if I say divided by 8 gets us So the mean is equal to So this is one way to kind of measure the center, the central tendency.
Another way is with the median. And this is to pick out the middle number, the median. And to figure out the median, what we want to do is order these numbers from least to greatest.
So it looks like the smallest number here is Then, the next one is There's no 22 here. Let's see, there's two 23's. So 23 and a And no 24's. There's a There's no 26, 27, There is a Then you have your And then you have your So what's the middle number now that we've ordered it? We already knew that. And so there's actually going to be two middles. If you have an even number, there's actually two numbers that qualify for close to the middle. And to actually get the median, we're going to average them.
So 23 will be one of them. That, by itself, can't be the median because there's three less than it and there's four greater than it. And 25 by itself can't be the median because there's three larger than it and four less than it. So what we do is we take the mean of these two numbers and we pick that as the median. So if you take 23 plus 25 divided by 2, that's 48 over 2, which is equal to So even though 24 isn't one of these numbers, the median is So this is the middle number.
So once again, this is one way of thinking about central tendency. If you wanted a number that could somehow represent the middle. You cannot add one to infinity, any more than you can add one to a person, or to love or hate.
Pipe ' ' is also also referred to as vertical bar, vbar, pike and has many uses in mathematics, physics and computing. When an object or point moves in a cyclic pattern, or is subject to vibration or oscillation e. See an introduction to geometry for more. The line connecting the centre of a regular polygon with one of its sides. The line is perpendicular at a right angle to the side. Geometric area is defined as the space occupied by a flat shape or the surface of an object.
Area is measured in square units, such as square metres m 2. For more, see our page on area, surface area and volume. An asymptote is a straight line or axis that is specifically related to a curved line.
As the curved line extends tends to infinity, it approaches, but never touches, its asymptote that is, the distance between the curve and the asymptote tends to zero. It occurs in geometry and trigonometry. A line of reference about which an object, point or line is drawn, rotated or measured.
In a symmetrical shape, an axis is usually a line of symmetry. A coefficient is a number or quantity multiplying another quantity.
It is usually placed before a variable. In the expression 6 x , 6 is the coefficient and x is the variable. The circumference is the length of the distance around the edge of a circle. It is a type of perimeter that is unique to circular shapes.
For more, see our page on curved shapes. Data are a collection of values, information or characteristics, which are often numerical in nature. They may be collected by scientific experiment or other observational means. They may be quantitative or qualitative variables. A datum is a single value of a single variable.
See our page on Types of Data for more. Diameter is a term used in geometry to define a straight line that passes through the centre of a circle or sphere, touching the circumference or surface at both ends. The diameter is twice the radius. Extrapolate is a term used in data analysis.
It refers to the extension of a graph, curve, or range of values into a range for which no data exists, inferring the values of unknown data from trends in the known data.
A factor is a number that we multiply by another number. A factor divides into another number a whole number of times. Most numbers have an even number of factors. A square number has an odd number of factors. A prime number has two factors — itself and 1. A prime factor is a factor that is a prime number. The mean average of a set of data is calculated by adding all numbers in the data set and then dividing by the number of values in the set. When the data set is ordered from least to greatest, the median is the middle value.
The mode is the number that occurs most times. The basic arithmetical operations are addition, subtraction, multiplication and division. The order in which operations are carried out in a calculation is important. The perimeter of a 2-dimensional shape is the continuous line or the length of the line that defines the outline of the shape. The perimeter of a circular shape is specifically called its circumference. Our page on Perimeter explains this in more detail.
Proportion is a relative of ratio. Ratios compare one part to another part, and proportions compare one part to the whole. Proportion is related to fractions. It is an important rule that applies only to right-angled triangles. Quantitative data are numeric variables or values that can be expressed numerically, i. Qualitative data are type variables that do not have a numerical value and may be expressed descriptively, i.
See our page on types of data for more. The radian is the SI unit for angular measurement. One radian is equivalent to the angle subtended at the centre of a circle by an arc equal in length to the radius.
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