2. Questions Bank
  3. 7th Class
  4. Mental Ability
  5. Data Handling

7th Class Mental Ability Data Handling Question Bank Data Handling

  • question_answer
    The traffic police recorded the speed (in km/h) of 10 motors as 47, 53, 49, 60, 39, 42, 57, 55, 48 and 52. Later on an error in the recording instrument was found. Find the correct mean speed of the motors if the instrument recorded the speed 6 km/h less in each case.

    A) 55.2 km/h 

    B)              56.2 km/h   

    C) 57.2 km/h 

    D)               58.2 km/h

    E) None of these

    Correct Answer: B

    Solution :

    Explanation Mean speed using error instrument \[=\,\,\,\frac{47+53+49+60+39+42+57+55+48+52}{10}\]\[=\,\,\frac{502}{10}=50.2\,\,km/h\] Corrected mean speed \[=\,\,\frac{53+59+55+66+45+48+63+61+54+58}{10}\]\[=\frac{562}{10}=56.2\,\,km/h\]


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