Question 1202982
Analysis of variance compares the means of a response variable for several groups. ANOVA compares the variation within each group to the variation of the mean of each group. The ratio of these two is the F statistic from an F distribution with (number of groups  -  1) as the numerator degrees of freedom and (number of observations minus number of groups) as the denominator degrees of freedom. 


the sample size of the groups is 4.
that would be the number of columns in the data set.
that says the number of groups is 4.
the degrees of freedom for the numerator is 4 minus 1 = 3


the sample size of the denominator is 7.
that would be the number of rows in the data set.
the total number of observations in the data set is 7 * 4 = 28


the degrees of freedom for the denominator is the number of total observations minus the number of groups = 28 minus 4 = 24


if this is right, the ceitical F at .01 level of significance would be the F for number of degrees of freedom for the numerator divided by the number of degrees of freedom for the denominator = F for column 3 intersect with row 24 = 4.718.


the critical F calculator gives the same resuls with greater precision as shown below.


<img src = "http://theo.x10hosting.com/2023/072501.jpg">


a good reference to give you an idea of what's happening can be found at <a href = "https://www.youtube.com/watch?v=-yQb_ZJnFXw" target = "_blank">https://www.youtube.com/watch?v=-yQb_ZJnFXw</a>