Question

The annual salaries (in thousands of dollars) for the employees of a small technology firm are as follows:

73	70	59	80	71	70	81	73
71	72	73	66	74	70	71	70
77	73	72	71	75	74	73	84

Construct a frequency table. Use 7 classes, start with a lower class limit of 59, and use a whole number for the class width.

Annual Salaries			Frequency
Answer	-	Answer	Answer
Answer	-	Answer	Answer
Answer	-	Answer	Answer
Answer	-	Answer	Answer
Answer	-	Answer	Answer
Answer	-	Answer	Answer
Answer	-	Answer	Answer

Answer 1

let us make class intervals of width 4 so that starting with 59 the last interval ends with 85 and it will include that largest value i.e., 87 and so that we will have 7 classes.

so the first class interval would be 59-63 and second would be 63-67 and so on. the last class interval would be 83-87.

Now the lower limit of a class interval is included while the upper limit is not included.

For frequency, let we will count all given data values that fall into that interval. For e.g., for the interval 59-63, we will count data values which will fall in this interval( or in 59-62 as upper limit is not included). From the given data we can see that only 1 data point lies in this interval hence frequency for this class interval is 1. And we will calculate the frequency for all the intervals in the same way.

Hence the Frequency table is as follows:

Annual Salaries			Frequency
59	-	63	1
63	-	67	1
67	-	71	4
71	-	75	13
75	-	79	2
79	-	83	2
83	-	87	1
Total			24