If you enter raw data, the tool will run the Shapiro-Wilk normality test and calculate outliers, as part of the test calculation.

oror enter summarized data ( n, S) below

Enter sample data

Header: You may change groups' name to the real names. Data: When entering data, press Enter after each value.

The tool will not count empty cells or non-numeric cells.

Enter sample data

You may copy data from Excel, Google sheets or any tool that separate data with Tab and Line Feed. Copy the data, one block of 2 consecutive columns includes the header, and paste below.

Copy the data,

It is okay to leave empty cells, empty cells or non numeric cells won't be counted

Sample data

validation message

Information

Target: To check if the difference between the population's standard deviations of two groups is significance, using sample data Example1: A man of average hight is expected to be 10cm taller than a woman of average hight (d=10) Example2: The average weight of an apple grown in field 1 is expected to be equal in weight to the average apple grown in field 2 (d=0)

Assumptions

Normal distribution - the F test for variances is very sensitive to the normality assumption.

Required Sample Data

S_{1},S_{2} -Sample standard deviations of group1 and group2

n_{1},n_{2} - Sample size of group1 and group2

R Code

The following R code should produce the same results:

Currently, there is no direct R function for the two-sample z test.