Select Board & Class

Login

Statistics

Question 7:

To find out the concentration of SO2 in the air (in parts per million, i.e., ppm), the data was collected for 30 localities in a certain city and is presented below:

concentration of SO2 (in ppm)

Frequency

0.00 − 0.04

4

0.04 − 0.08

9

0.08 − 0.12

9

0.12 − 0.16

2

0.16 − 0.20

4

0.20 − 0.24

2

Find the mean concentration of SO2 in the air.

Answer:

To find the class marks for each interval, the following relation is used.

Class size of this data = 0.04

Taking 0.14 as assumed mean (a), di, ui, fiui are calculated as follows.

...

Concentration of SO2 (in ppm)

Frequency

fi

Class mark

xi

di = xi − 0.14

To view the solution to this question please

What are you looking for?

Syllabus