STATISTICAL TECHNIQUES AND TOOLS
ANALYSIS OF VARIANCE
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Question
[CLICK ON ANY CHOICE TO KNOW THE RIGHT ANSWER]
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df between = k-1
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df between = N-k
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df between = k-N
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None of the above
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Detailed explanation-1: -In order to determine the critical value of F we need degrees of freedom, df1=k-1 and df2=N-k. In this example, df1=k-1=3-1=2 and df2=N-k=18-3=15. The critical value is 3.68 and the decision rule is as follows: Reject H0 if F > 3.68.
Detailed explanation-2: -Degrees of Freedom Formula Some calculations of degrees of freedom with multiple parameters or relationships use the formula Df = N-P, where P is the number of different parameters or relationships. For example, in a 2-sample t-test, N-2 is used because there are two parameters to estimate.
Detailed explanation-3: -Two Group ANOVA df2 = n – k. The “k” in that formula is the number of cell means or groups/conditions. For example, let’s say you had 200 observations and four cell means. Degrees of freedom in this case would be: Df2 = 200 – 4 = 196.
Detailed explanation-4: -The F distribution has two different degrees of freedom: df1 and df2. The formula for df1 is the following: d f 1 = g − 1 where g is the amount of groups. The formula for df2 is the following: d f 2 = N − g where N is the sample size of all groups combined and g is the number of groups.