STATISTICS

Statistics

Is a branch of mathematics with it's own concepts, methods and values, which find many applications in geography and other disciplines

Mean, Median, Mode

Measures of Central Tendency

Measures of Central Tendency

Calculates the location of the central point using a different method

Mean

Known as Arithmetic Average

Mean

Calculating the ___. Just add up all the values and divide the sum by the number of values

Mean

Incorporates all values in the data

Sigma

Usual way of indicating a SUMMATION; Greek letter

Sigma

Summation Notation

Summation Notation

Indicates the sum of all the numbers in a given set

_____ portion of a _____ group are used to obtain information about the entire group

Small, Large

Population

Entire Group

Samples

Small portions

μ(mu)

The mean of a population denoted by the Greek letter

x bar

The mean if a sample

Median

the middle value

Median

The value that splits the data set in half

To find the ____. Arrange your data to smallest to largest. The ____ is the middle value if the number is ____. The ____ is the mean of the two middle values if the number of values is ____

Median, median, odd, median, even

Mode

The value that occurs most frequently in a list of values

Multimodal Distribution

If the list has multiple values that are tired of occurring the most frequently

No mode

If no numbers occurs more than often than the other numbers

Weighted mean

Some data are more important than others

Weighted mean

We multiply each value or number by the weight assigned to it, get the sum of all products, and divide the sum by the total number of weights

Dispersion

Is the spread or variation of data.

Dispersion

It tells us how far apart the data values are

Two sets of data can have the same mean but ____.

Different spread

Range, Standard Deviation

Measures of Dispersion

Range

The difference between the greatest value and smallest value

Range

It does not give information about the spread of each value from the sum; sensitive to extreme values(outliers)

Standard Deviation

Is a measure of Dispersion which does not depend on the extreme values

Standard Deviation

It makes use of the amount by which individual value or number deviated or differs from the mean

Standard Deviation

Shows how far each data value if from the mean(average)

Deviation

Is the difference between a data value and the mean

Standard Deviation

Uses the SUM OF THE SQUARES of the deviation

Variance

Another statistical tool used to measure Dispersion

Variance

Is the Square of the Standard Deviation of the data

To get the Variance of the sample: we ____ it's standard deviation

Square