Q13 of 141 Page 8

The arithmetic mean of the following data is 14. Find the value of k.



















xi:



5



10



15



20



25



yi:



7



k



8



4



5







































X



y



yx



5



7



35



10



K



10k



15



8



120



20



4



80



25



5



125




N = 24 + k



∑yx = 360 + 10k



Given,


Mean = 14


= 14


= 14


360 + 10k = 336 + 14k


24 = 4k


k = 6


Hence, the value of k is 6


More from this chapter

All 141 →
11

Five coins were simultaneously tossed 1000 times and at each toss the numbers of heads were observed. The number of tosses during which 0, 1, 2, 3, 4 and 5 heads were obtained are shown in the table below. Find the mean number of heads per toss.



































No. of heads per toss



No. of tosses



0



38



1



144



2



342



3



287



4



164



5



25



Total



1000


 12

Find the missing frequencies in the following frequency distribution if it is known that the mean of the distribution 50.

















x: 10



30



50



70



90



y: 17



f1



32



f2



19


 14

The arithmetic mean of the following data is 25, find the value of k.



















xi:



5



15



25



35



45



yi:



3



k



3



6



2



[CBSE 2001]

 15

If the mean of the following data is 18.75. Find the value of p.



















xi:



10



15



p



25



30



yi:



5



10



7



8



2