Mathematics
Find the mean of 25 given numbers when the mean of 10 of them is 13 and the mean of the remaining numbers is 18.
Related Questions
In a class test, the mean of marks scored by a class of 40 students was calculated as 18.2. Later on, it was detected that the marks of one student was wrongly copied as 21 instead of 29. Find the correct mean.
Find the mean of the following distribution :
Number Frequency 5 1 10 2 15 5 20 6 25 3 30 2 35 1 The contents of 100 matchboxes were checked to determine the number of matches they contained.
No. of matches No. of boxes 35 6 36 10 37 18 38 25 39 21 40 12 41 8 (i) Calculate, correct to one decimal place, the mean number of matches per box.
(ii) Determine how many extra matches would have to be added to the total contents of the 100 boxes to bring the mean upto exactly 39 matches.