Statistics: The
Interpertation of Data

There are a variety of ways to represent data depending on what type of data you have, you will then choose what type of graph to use.

Dot Plots are used to summarize relatively small sets of data.

Stem and Leaf Plots are also used to summarize relatively small sets of data.

Histograms use data that is grouped into intervals.

Line Graphs can use a variety of data.

Bar Graphs use categorical data, where the horizontal scale may be some nonnumerical attribute.

Pie Charts represents relative amounts to a whole.

Pictographs are useful in comparing quantities.

Mean: The arithmetic mean, or average. The formula for mean:S divided by NS= the sum of the valuesN= the number of values

Median: the middle value in a collection when the values are arranged in order of increasing size. Data values are written in order of increasing size,If the amount of numbers are odd, the median is the middle value in the list.If the amount of numbers are even, the median is the average of the two middle values.

Mode: the value that occurs most frequently in a collection of values. If two or more values occur equally often and more frequently than all other values, there are two or more modes.

Range: the difference between the smallest and largest data values. Interquartile Range (IQR): is the difference between the upper and the lower quartile.

Quartiles: casually speaking, these values divide the data set into four sections, each of which contains, in increasing order, about 1/4 of the data. Lower Quartile: is the median of the first half of the data values.Upper Quartile: is the median of the last half of the data values.

Standard Deviation: A measure of the typical deviation from the mean.

Outlier: in a set of data is a data value that does not seem to makes sense with the rest of the data. A number being very small or very large.

A box plot, or Box and Whisker Plot, consist of a central bow extending from the lower to the upper quartile, with a line marking the median and line segments, or whiskers, extending outward from the box to the extremes.

the theory, methods, and practice of forming judgments about the parameters of a population and the reliability of statistical relationships, typically on the basis of random sampling.

Population is a particular set of objects about which one desires information.

Sample is a subset of the population.

A Random Sample of size is a subset of individuals from the population chosen in such a way that every such subset has an equal chance of being chosen.

For a population that has a normal distribution, about 68% falls within 1 standard deviation of the mean, about 95% falls within 2 standard deviations of the mean, and about 99.7% falls within 3 standard deviations.

Percentile: each of the 100 equal groups into which a population can be divided according to the distribution of values of a particular variable.

A Z-score is a statistical measurement of a score's relationship to the mean in a group of scores.