00:01
We are given with number of observations n equal to 20 and the data are given is 13, 19, 68, 33, 45, 62, 15, 22, 43, 27, 62, 60, 54, 38, 30, 35, 16, 45, 65, 65, 65, 65, 62, and 33.
00:28
Now we can form this as a continuous type of data so the class intervals we can take it as 10 to 20 20 30 30 to 40 40 50 50 50 50 50 60 and 60 to 70 and 60 to 70 and we have to find the tally marks because on which class interval the given data falls so we have to mark all the values put for each entry as one and frequency 4 3 4 3 3 3 and mid value m is 15 25 35 35 45 and 65 and we have to find the fm so which is 60 75 75 140 135 135 135 and the total is 770 and frequency is 20.
01:36
Now to find the standard deviation we need to find fm square which is 900 -1875 49000 6075 -9075 1 -2 -675 -5 and the total is 385 -0 -0...