the two consecutive class marks of a distribution are 52 and 57. find the class limits of two intervals

class marks are 52 , 57

Therefore class size = 57-52=5

Now we know lower and upper class limits for 52 are

lower limit=52 - 5/2=49.5 

upper limit=52+5/2= 54.5

Now for 57

lower limit= 57-5/2= 54.5

upper limit = 57+5/2= 59.5

Therefore we obtain