Stats with Excel by.net



Stats with Excel

The first thing you need to make sure of is that the Statistics Tool is enabled in Excel. If you don’t see a Tools > Data Analysis (Excel 2003) or Data Analysis (Excel 2007) option, do the following:

(Excel 2003) Tools > Add-ins > Analysis ToolPak;

(Excel 2007) Excel Options > Add-ins > Manage Add-ins > Analysis ToolPak

Some of these functions do not require the ToolPak, but it is handy to install it anyway and it doesn’t take up any extra space.

You can do both descriptive and inferential statistics with Excel

Descriptive statistics “describe” the data of a sample or population.

Average (Mean) GPA

Standard Deviation of SAT score

Inferential statistics “infer” (i.e. conclude) relationships between a sample AND a population, or “infer” past, present or future results of a sample/population based on its data.

Regression/correlation analysis of GPA and SAT (relationship between SAT and GPA)

Functions in Excel

In Excel, hit the equal “=” sign to begin a formula (or you can pick Insert Function from the menu). In the following examples, the brackets { } will be used to show when the formula begins and ends, but you do NOT use those brackets in Excel. Range can be selected with the mouse, OR you can pick one cell then hit the period “.” key to be able to pick the end of the range.

Mean { =average(range) }

You can compute mode { =mode(range) } or median {=median(range) }, but use them when appropriate.

Standard Deviation { =stdev(range) }

You can also count the number of instances of a value including instances of text:

{ =countif(range,”value”) }

The following example would count every instance of “male” in the range:

=countif(A2:A7,”male”)

You can create frequency distribution histograms by using:

Tools -> Data Analysis, then Historgram

You can create a complete descriptive statistics table of an array ( a range of numbers) by using:

Tools > Data Analysis > Descriptive Statistics /> Summary Statistics

You can do f-tests (FTEST), Student’s t-tests (TTEST), and correlations (CORREL) in Excel too, but you should only use these functions if you have some experience with statistics and can interpret the results in a professional way.

Writing Statistics

Writing about your findings is similar in MLA and APA style, but what follows is the strict APA style; follow these general rules:

Population = N

Sub-population = n

Standard Deviation = SD

Mean = M

Statistics are often written in parentheses after an item that the statistic refers to. The test abbreviation should be italicized, and symbols and numbers should be separated by a space. In the following two examples, the M here is referring to a Likert-type scale.

In a survey of DU students, participants (N = 100) responded that money was more important (M = 4.2, SD = .9) than experience (M = 3.5, SD = .76) in selecting a summer job.

In a survey of computer game addicts, females (n = 15) were more likely to be depressed during withdrawal (M = 5.2, SD = .45) than males were (n = 78, M = 3.2, SD = .98)

................
................

In order to avoid copyright disputes, this page is only a partial summary.

Google Online Preview   Download