F Test Table 95 Confidence. F table for two tailed test at α 0 05 95 confidence level. More specifically a test statistic is computed with ν 1 and ν 2 degrees of freedom and the result is compared to this table.
For the f test you can perform a 2 tailed test by multiplying the confidence level p by 2 so from a table for a 1 tailed test at the p 0 05 confidence level we would perform a 2 tailed test at p 0 10 or a 90 confidence level. How to use this table this table contains the upper critical values of the f distribution this table is used for one sided f tests at the α 0 05 0 10 and 0 01 levels. The following image shows how to calculate a 95 confidence interval for the ratio of population variances in excel.
When referencing the f distribution the numerator degrees of freedom are always given first as switching the order of degrees of freedom changes the distribution e g f 10 12 does not equal f 12 10 for the four f tables below the rows represent denominator degrees of.
The column headings give the numerator degrees of freedom and the row headings the demoninator degrees of freedom. Thus the 95 confidence interval for the ratio of the population variances is 0 4148 4 4714. Lower one sided critical values may be found from these tables by reversing the degrees of freedom and using the reciprocal of the tabled value at the same significance level 100 minus the percent for the percentile. We are now ready to test the null hypothesis which assumes that there is no difference between aerial from in the five different groups of test subjects.
