Using the given information, the value of Σfd is 800
From the question, we are to determine the value of Σfd
The formula for mean, using the assumed mean method is given by
[tex]\bar x = A + \frac{\sum fd}{\sum f}[/tex]
Where [tex]\bar x[/tex] is the mean
A is the assumed mean
From the given information,
[tex]\bar x = 80[/tex]
[tex]A = 60[/tex]
[tex]\sum f = 40[/tex]
Putting the parameters into the equation, we get
[tex]80 = 60 + \frac{\sum fd}{40}[/tex]
[tex]80-60 = \frac{\sum fd}{40}[/tex]
[tex]20 = \frac{\sum fd}{40}[/tex]
[tex]\sum fd = 20 \times 40[/tex]
[tex]\sum fd = 800[/tex]
Hence, the value of Σfd is 800
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