Q9 of 145 Page 417

Find the mean of the following frequency distribution:

















Class



1 - 3



3 - 5



5 - 7



7 - 9



Frequency



9



22



27



18


For equal class intervals, we will solve by finding mid points of these classes using direct method.







































CLASS



MID - POINT(xi)



FREQUENCY(fi)



fixi



1 - 3



2



9



18



3 - 5



4



22



88



5 - 7



6



27



162



7 - 9



8



18



144



TOTAL




76



412




We have got


Σfi = 76 & Σfixi = 412


∵ mean is given by



⇒


⇒


Thus, mean is 5.421


More from this chapter

All 145 →
7

Consider the following frequency distribution:



















Class



0 - 5



6 - 11



12 - 17



18 - 23



24 - 29



Frequency



13



10



15



8



11



Find the upper limit of the median class.

 8

The annual profits earned by 30 shops of a shopping complex in a locality are recorded in the table shown below:



































Profit (in lakh Rs.)



Number of shops



More than or equal to 5



30



More than or equal to 10



28



More than or equal to 15



16



More than or equal to 20



14



More than or equal to 25



10



More than or equal to 30



7



More than or equal to 35



3



If we draw the frequency distribution table for the above data, find the frequency corresponding to the class 20 - 25.

 10

The maximum bowling speeds (in km/hr) of 33 players at a cricket coaching centre are given below:

















Speed in km/hr



85 - 100



100 - 115



115 - 130



130 - 145



No. of players



10



4



7



9



Calculate the median bowling speed.

 11

The arithmetic mean of the following frequency distribution is 50.



















Class



0 - 10



10 - 20



20 - 30



30 - 40



40 - 50



Frequency



16



p



30



32



14



Find the value of p.