Question

step by step explanation.
Plz help me solve this question ​

Answer 1

$\implies {\rm Mean = \frac{Sum \: \: Of \: \: Frequency}{Number \: \: of \: \: Frequency}}$

$\implies \sf 18 = \frac{3 + 6 + 9 + 13 + f + 5 + 4}{7}$

$\implies \sf 18 = \frac{40+ f }{7}$

$\implies \text{18 × 7 = 40 + f }$

$\implies \text{126 = 40 + f }$

$\implies \text{126 - 40 = f }$

$\implies \text{86 = f }$

$\implies \boxed{ \text{f = 86 }}$

I hope it helps you...

Answer 2

Answer:

\begin{gathered} \implies {\rm Mean = \frac{Sum \: \: Of \: \: Frequency}{Number \: \: of \: \: Frequency}} \\ \end{gathered}

⟹Mean=

NumberofFrequency

SumOfFrequency

\begin{gathered} \implies \sf 18 = \frac{3 + 6 + 9 + 13 + f + 5 + 4}{7} \\ \end{gathered}

⟹18=

7

3+6+9+13+f+5+4

\begin{gathered} \implies \sf 18 = \frac{40+ f }{7} \\ \end{gathered}

⟹18=

7

40+f

\begin{gathered} \implies \text{18 × 7 = 40 + f } \\ \end{gathered}

⟹18 × 7 = 40 + f

\begin{gathered} \implies \text{126 = 40 + f } \\ \end{gathered}

⟹126 = 40 + f

\begin{gathered} \implies \text{126 - 40 = f } \\ \end{gathered}

⟹126 - 40 = f

\begin{gathered} \implies \text{86 = f } \\ \end{gathered}

⟹86 = f

\begin{gathered} \implies \boxed{ \text{f = 86 }} \\ \end{gathered}

⟹

f = 86

I hope it helps you...