2. Solved Papers
  3. Railways

Railways RRB (Assistant Loco Pilot & Technician) Solved Paper-2 (2014)

  • question_answer
    If the mean of the following data is 13.5, then the value of p is
    x 5 10 p 20 25
    f 10 10 10 2 8

    A)  15                              

    B)  150

    C)  10                              

    D)  None of these

    Correct Answer: A

    Solution :

    \[{{x}_{i}}\] \[{{f}_{i}}\] \[{{f}_{i}}\times {{x}_{i}}\]
    5 10 50
    10 10 100
    p 10 10p
    20 2 40
    25 8 200
    \[\Sigma {{f}_{i}}=40\] \[\Sigma {{f}_{i}}{{x}_{i}}=10p+390\]
    \[\therefore \] Mean \[(\bar{x})=\frac{\Sigma {{f}_{i}}{{x}_{i}}}{\Sigma {{f}_{i}}}=\frac{10p+390}{40}\] \[\Rightarrow \]            \[135=\frac{10p+390}{40}\] \[\Rightarrow \]            \[135\times 40=10p+390\] \[\Rightarrow \]            \[540-390=10p\] \[\therefore \]    \[p=\frac{150}{10}=15\]


You need to login to perform this action.
You will be redirected in 3 sec spinner