Q13 of 141 Page 7



















Class interval:



25-35



35-45



45-55



55-65



65-75



Frequency:



6



10



8



12



4


Let the assumed mean (A) = 50



























































Class interval



Mid value



di = xi - 50



ui =



Frequency (fi)



fiui



25-35



30



-20



-2



6



-12



35-45



40



-10



-1



10



-10



45-55



50



0



0



8



0



55-65



60



10



1



12



12



65-75



70



20



2



4



8







N = 40



∑fiui = -2



We have, A = 50


h = 10


Mean = A + h *


= 50 + 10 *


= 50 – 0.5


= 49.5


More from this chapter

All 141 →
11



















Class interval:



0-8



8-16



16-24



24-32



32-40



Frequency:



5



6



4



3



2


 12





















Class interval:



10-30



30-50



50-70



70-90



90-110



110-130



Frequency:



5



8



12



20



3



2


 14























Classes:



25-29



30-34



35-39



40-44



45-49



50-54



55-59



Frequency:



14



22



16



6



5



3



4


 15

For the following distribution, calculate mean using all suitable methods:

















Size of items:



1-4



4-9



9-16



16-27



Frequency:



6



12



26



20