1.

Find the medianclass interval frequency0-1000 2501000-2000 1902000-3000 1003000-4000 404000-5000 155000-6000 5​

Answer»

\large\underline{\sf{Solution-}}

\begin{gathered}\begin{gathered}\begin{gathered}\boxed{\begin{array}{c|c|c}\sf Class\: interval&\sf Frequency\: (f)&\sf \: <klux>CUMULATIVE</klux> \: frequency\\\frac{\qquad \qquad \qquad}{}&\frac{\qquad   \qquad}{}\\\sf 0 - <klux>1000</klux>&\sf 250&\sf250\\\\\sf 1000 - 2000 &\sf 190&\sf440\\\\\sf 2000-3000 &\sf 100&\sf540\\\\\sf 3000 - 4000&\sf 40&\sf580\\\\\sf 4000-5000&\sf 15&\sf595\\\\\sf 5000-6000&\sf 5&\sf600\\\frac{\qquad}{}&\frac{\qquad}{}\\\sf & \sf & \end{array}}\end{gathered}\end{gathered}\end{gathered}

we know that

  • N = 60 and N/2 = 300

The cumulative frequency just greater than 300 is 440 and the corresponding class is 1000 - 2000

Median formula :

\boxed{ \sf M= l + \Bigg \{h \times \dfrac{ \bigg( \dfrac{N}{2} - cf \bigg)}{f} \Bigg \}}

Here,

  • l denotes lower limit of median class

  • h denotes width of median class

  • f denotes frequency of median class

  • cf denotes cumulative frequency of the class preceding the median class

  • N denotes sum of frequency

ACCORDING to the question,

  • median class is 1000 - 2000

so,

  • l = 1000,

  • h = 1000,

  • f = 190,

  • cf = cf of preceding class = 250

  • N/2 = 300

By substituting all the given values in the formula,

\sf \: \:  \:  \:  M =  \:  \: 1000 + \bigg(\dfrac{300 - 250}{190}  \bigg) \times 1000

\sf \: \:  \:  \:  M =  \:  \: 1000 + \dfrac{5000}{19}

\sf \: \:  \:  \:  M =  \:  \: 1000 + 263.16

\sf \: \:  \:  \:  M =  \:  \: 1263.16

─━─━─━─━─━─━─━─━─━─━─━─━─

Additional Information :-

Mean :-

Using Direct Method

\dashrightarrow\sf Mean = \dfrac{ \sum f_i x_i}{ \sum f_i}

Using Short Cut Method

\dashrightarrow\sf Mean = \: A \:  +  \dfrac{ \sum f_i d_i}{ \sum f_i}

ASSUMED Mean Method :-

\dashrightarrow\sf Mean = \: A \:  +  \dfrac{ \sum f_i u_i}{ \sum f_i} \times h



Discussion

No Comment Found

Related InterviewSolutions