Question

The mean of the following data is 21.6, find p
xi- 6, 12, 18, 24, 30, 36
fi- 5, 4, p, 6, 4, 6

Answer 1

p=5
i hope it will help u!!!

Answer 2

$\begin {tabular} {| c | c | c | } </p><p>\cline { 1-3} x_{I} & f_{i} & f_{i} x_{i} \\</p><p>\cline {1-3} 6&5&30 \\</p><p>\cline {1-3} 12&4&48 \\</p><p>\cline {1-3} 18&p&18p \\</p><p>\cline {1-3} 24&6&144 \\</p><p>\cline {1-3} 30&4& 120 \\</p><p>\cline {1-3} 36&6&216 \\</p><p>\cline {1-3} - & \sum f_{i} = 25+p & \sum {f_{i} x_{i} } = 558 + 18p \\</p><p>\cline {1-3} </p><p>\end {tabular}$

$Mean\: (\overline {x}) = 21.6 \: (given)$

$\implies \frac{\sum {f_{i} x_{i}}}{\sum f_{i} } = 21.6$

$\implies \frac{558+18p}{25+p} = 21.6$

$\implies 558 + 18p = 21.6(25+p)$

$\implies 558 + 18p = 540 + 21.6p$

$\implies 558 - 540 = 21.6p - 18p$

$\implies 18 = 3.6p$

$\implies \frac{18}{3.6} = p$

$\implies \frac{180}{36} = p$

$\implies 5 = p$

Therefore.,

$\red { Value \:of \:p } \green {= 5}$

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