10th Class Mathematics Solved Paper - Mathematics-2018

  • question_answer
    The mean of the following distribution is 18. Find the frequency f of the class 19 ? 21.
    Class 11 ? 13 13 ? 15 15 ? 17 17 ? 19 19 ? 21 21 ? 23 23 ? 25
    Frequency 3 6 9 13 f 5 4
    OR
    The following distribution gives the daily income of 50 workers of a factory:
    Daily Income (in Rs.) 100 ? 120 120 ? 140 140 ? 160 160 ? 180 180 ? 200
    Number of workers 12 14 8 6 10
    Convert the distribution above to a less than type cumulative frequency distribution and draw it?s give.

    Answer:

    C.I. Mid value \[{{x}_{i}}\] \[{{f}_{i}}\] \[{{f}_{i}}{{x}_{i}}\]
    11 ? 13 12 3 36
    13 ? 15 14 6 84
    15 ? 17 16 9 144
    17 ? 19 18 13 234
    19 ? 21 20 f 20f
    21 ? 23 22 5 110
    23 ? 25 24 4 96
    Total \[\sum{{{f}_{i}}=40+f}\] \[\sum{{{f}_{i}}{{x}_{i}}=704+20f}\]
                Now,                 Mean = 18                    (Given)
                \[\Rightarrow \]               \[\frac{\sum{{{f}_{i}}{{x}_{i}}}}{\sum{{{f}_{i}}}}=18\]
                \[\therefore \]                  \[\frac{704+20f}{40+f}=18\]
                \[\Rightarrow \]               \[704+20f=18(40+f)\]
                \[\Rightarrow \]               \[704+20f=720+18f\]
                \[\Rightarrow \]               \[20f-18f=720-704\]
                \[\Rightarrow \]                          \[2f=16\]
                \[\Rightarrow \]                            \[f=8\]
    OR
    Less than type cumulative frequency distribution:
    Daily Income No. of workers
    Less than 120 12
    Less than 140 26
    Less than 160 34
    Less than 180 40
    Less than 200 50


adversite


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

Free
Videos