The answer is: " 21 ".
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Twenty-one (21) individuals participated in the study.
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Step-by-step explanation:
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In this case:
"degrees of freedom" {df) = n - 1 = 20 ;
in which:
"n" refers to the "sample size" ;
that is ; the "total number of individuals who participated in the study" .
" n - 1 = 20 " ; Solve for "n" ;
Add "1" to each side of the equation:
n - 1 + 1 = 20 + 1 ;
n = 21 ;
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The answer is: " 21 ".
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