The distance (in km) of 40 engineers from their residence to their place of work were found as follows :
`{:(5,3,10,20,25,11,13,7,12,31),(19,10,12,17,18,11,32,17,16,2),(7,9,7,8,3,5,12,15,18,3),(12,14,2,9,6,15,15,7,6,12):}`
Construct a grouped frequency distribution table with class size for the data given above taking the first interval as 0-5 (5 not included). What main features do you observe from this tabular representation ?

Thirty children were asked about the number of hours they watched TV programmes in the previous week.The results were found as follows : {:(1",",6",",2",",3",",5",",12",",5",",8",",4",",8),(10",",3",",4",",12",",2",",8",",15",",1",",17",",6),(3",",2",",8",",5",",9",",6",",8",",7",",14",",12):} (i) Make a grouped frequency distribution table for this data 5 and one of the class intervals as 5-10. (ii) How many children watched television for 15 or more hours a weak ?

The relative humidity (in %) of a certain city for a month of 30 days was as follows : {:(98.1,98.6,99.2,90.3,86.5,95.3,92.9,96.3,94.2,95.1),(89.2,92.3,97.1,93.5,92.7,95.1,97.2,93.3,95.2,97.3),(96.2,92.1,84.9,90.2,95.7,98.3,97.3,96.1,92.1,89):} (i) Construct a grouped frequency distribution table with classes 84-86 ,86-88, etc.

A company manufactures car batteries of a particular type. The lives (in years) of 40 such batteries were recorded as follows : {:(2.6,3.0,3.7,3.2,2.2,4.1,3.5,4.5,3.5,2.3,3.2),(3.4,3.8,3.2,4.6,3.7,2.5,4.4,3.4,3.3,2.9,3.0),(4.3,2.8,3.5,3.2,3.9,3.2,3.2,3.1,3.7,3.4,4.6),(3.8,3.2,2.6,3.5,4.2,2.9,3.6,,,,):} Construct a grouped frequency distribution table for this data, using class intervals of size 0.5 starting form the intervals 2-2.5

If A={(3,6,9,12,15,18,21},B={4,8,12,16,20},C={2,4,6,8,,10,12,14,16} and D={5,10,15,20} find: A-D

If A={(3,6,9,12,15,18,21},B={4,8,12,16,20},C={2,4,6,8,,10,12,14,16} and D={5,10,15,20} find: D-B

Find the mean deviation about the median for the following data 3, 9, 5, 3, 12, 10, 18, 4, 7, 19, 21.

A study was conducted to find out the concentration of sulphur dioxide in the air in parts per million (ppm) of a certain city. The data obtained for 30 days is as follows : {:(0.03,0.08,0.08,0.09,0.04,0.17),(0.16,0.05,0.02,0.06,0.18,0.20),(0.11,0.08,0.12,0.13,0.22,0.07),(0.08,0.01,0.10,0.06,0.09,0.18),(0.11,0.07,0.05,0.07,0.01,0.04):} (i) Makes a grouped frequency distribution table for this data with class intervals as 0.00-0.04,0.04-0.08, and so on.

Find the mean deviation about the mean for the following data : 2, 4, 5, 7, 8, 10, 12, 17, 19, 26