Question

class interval 0- 5 ,5- 10 ,10 -15 ,15 -20 class mark a, b, 12.5 , 17.5p​

Answer 1

Answer:

Let the upper and lower limits be a and b respectively.

( Upper limit+ lower limit )/2 = 42

Now substitute the values in the above equations.

a -b = 42

Now, 2a= 94

a=47

b= 47-10= 37.

So upper and lower limits are 47 & 37