This calculator will tell you the two-tailed area under the standard normal curve, given a Z-score (i.e., the two-tailed probability from +/- the Z-score to infinity on both tails of the distribution). Please enter the necessary parameter values, and then click 'Calculate'. ...
Vendors using two-tailed tests according to the ConversionXL article (Jul 2015), include: Optimizely, VWO (Visual Website Optimizer), Adobe Target, Maxymiser, Convert, Monetate. A vendor I can guarantee is using a one-tailed test: Analytics-Toolkit.com with ourA/B Testing CalculatorandStatistica...
Instructions:This calculator conducts a Z-test for two population means (\(\mu_1\) and \(\mu_2\)), with known population standard deviations ( \(\sigma_1\) and \(\sigma_2\)). Please select the null and alternative hypotheses, type the significance level, the sample means, the popula...
What if the population standard deviations are known? The main purpose of this calculator is for comparing two population mean when sigma is unknown for both populations. In case that the population standard deviations are known, then you should use instead thisz-test for two means....
A good calculator for the McNemar exact test should also provide a confidence interval with the desired confidence level in its output, but very few do. Referring to Figure 2 (output from the MeasuringU®Usability Statistics Package Expanded), the 95% confidence interval around the difference ra...
The F-test for equality of two variances, compares the variances of two populations. Under the null hypothesis, it is assumed that the variances are equal. How to use the f test calculator? Choose the tails: The one-tailed test, left or right, is more powerful than the two-tailed test...
family. We assess the genomic structures, searched for synteny blocks representing conserved evolution of all HS-related genes at each synthesis step, and test the presence of critical loci for HS biosynthesis enzymes via gain-of-function and loss-of-function mutations across two types of species....
The study was randomized and blinded. Randomization was performed by block of 4 animals per day (i.e. 2 animals were randomly allocated to the 2 experimental groups, RIC or control, each day) using a randomization table generated by GraphPad online calculator QuickCalcs (https://www.graphpad....
This test demonstrates quite robust results even for a small number of subjects. Globally, a two-tailed p value of less than 0.05 was considered to indicate statistical significance. All statistical analyses were performed using GraphPad Prism 7 and R software (version 3.2.0). In the VC, ...
If a two-tailed test is used, p-value is the area in both tails. p-value can be found using one of several methods: Normal distribution probability z-table. Examples can be found on the web. It is important to read the table description to note what probability is listed by the ...