Math, asked by Nandy10101, 8 months ago

If the mean of frequency distribution is 7.5 and ∑fixi=120+3k,∑fi=30,

then l is equal to;

a)40 b)35 c)50 d)45​

Answers

Answered by gargkanchan30
0

Answer:

45 is the correct answer

Answered by mysticd
4

 Given \: mean \: of \: frequency \: distribution \\is \: 7.5 \: and

 \sum f_{i}x_{i} = 120 + 3k ,

 \sum f_{i} = 30

/* We know that */

\boxed{ \pink{ Mean = \frac{\sum f_{i}x_{i}}{\sum f_{i}} }}

 \implies 7.5 = \frac{120 + 3k }{ 30 }

 \implies 7.5 \times 30 = 120 + 3k

 \implies 225 = 120 + 3k

 \implies 225 - 120 = 3k

 \implies 105  = 3k

 \implies 3k = 105

 \implies k = \frac{105}{3}

 \implies k = 35

Therefore.,

 \red{ Value \: of \: k } \green { = 35 }

 Option \: \green { ( b ) } \: is \: correct

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