If x and y are the lower limit and upper limit respectively of a class interval, then (y - x) gives the :

1. class mark

2. class size

3. range

4. frequency

In a grouped frequency distribution , the cumulative frequency of the last class interval denotes :

1. the frequency pertaining to that class

2. the maximum value of the variate

3. the total number of observations

4. none of these

If the class-intervals in a frequency distribution are 1 - 11, 11 - 21, 21 - 31, etc., then class 1 - 11 means :

1. more than 1 and less than 11

2. 1 or more but less than 11

3. equal to or more than 1 but equal to or less than 11

4. more than 1 but less than or equal to 11

Directions:

Study the following table carefully and answer the questions that follow:

Based on above table, answer the following questions:

17. The total number of employees is :

(a) 30
(b) 31
(c) 55
(d) Cannot be determined

18. How many employees are less than 50 years of age?

(a) 9
(b) 18
(c) 27
(d) 31

19. How many employees are atleast 40 years old?

(a) 12
(b) 18
(c) 19
(d) 27

20. What is the difference between the class-mark of the first and last class intervals?

(a) 20
(b) 22.5
(c) 25
(d) 27.5