If 1-5, 6-10, 11-15, ........, are classes of a frequency distribution, then the mid-value of class 11-15 is ______.

If 1-5 , 6-10 , 11-15 , ..., are the classes of a frequency distribution , then the size of the class is "_______" .

If 1-5 , 6 -10 , 11-15 , 16-20, ..., are the classes of a frequency distribution , then the lower boundary of the class 11-15 is "_______" .

1-5 , 6-10 , 11-15 , ....... , are the classes of a distribution , the upper boundary of the class 1-5 is "_______"

If 1-10, 11-20, 21-30, 31-40, ......., are the classes of a frequency distribution, then the upper boundary of the class 31-40 is _____.

The mid value of the class 10 - 19 is

The mid value of the class 10-19 is ........

Consider the following distribution: The frequency of the class 10 -15 is _________.

Mid value of the class 10 - 20 is ......

If the class intervals of a frequency distribution are 1-10, 11-20, 21-30, ….,51-60 then the size of even class is

Find the class mark of the class 11 to 15.