(a) What is the lower limit of the second class interval?
The lower limit of the second class interval 20 – 30 is 20.
(b) What is the upper limit of the last class interval?
The upper limit of the last class interval 50 – 60 is 60.
(c) What is the frequency of the third class?
The frequency of the third class 30 – 40 is 4.
(d) Which interval has a frequency of 10?
Second class interval 20 – 30 has a frequency of 10.
(e) Which interval has the lowest frequency?
Third interval 30 – 40 has the lowest frequency i.e. 4.
(f) What is the class size?
The difference between the upper and lower limit of a class interval is called the Size of the class interval.
Size = Upper limit – Lower limit
= 20 – 10
= 10