Standard deviation of a data is given by ______.

If ⋋is the variance and o is the S.D. then ______.

The mean deviation of the series a, a + d, a + 2d, .... a + nd from its mean is ______.

If the S. D. of a set of observation is 8 and if each observation is divided by- 2 then S.D. of new set of observation is ______.

Find the variance of the data 6,5,9,13,12,8 and 10.

Find the mean deviation about the mean for the following data
36,72,46,60,45,42,53,49,51,46

The analysis of daily wages paid to workers in two firms A and B belonging to the same industry are:

(i) Which firm A or B pays more in total daily wages?
(ii) Which A or B shows greater variability in wages?

Find the variance of the following data:

Find the variance and standard deviation for the following data, 6,7,10,12,13,4,8,12.

Two plants A and B of a factory show following results about the number of workers and the wages paid to them.

Which plant, A or B shows greater variability in individual wages?

Find the mean deviation about the median for the data 34,66,30,38,44,50,40,60,42,51.

The following is the record of goals scored by team A in a football session.

For the team B, mean number of goals scored per match 2 with standard deviation 1.25 goals. Find which team may be considered more consistent?

Find the mean deviation from the mean for the following data
6, 5, 5.25, 5.5, 4.75, 4.5, 6.25, 7.75, 9.

Calculate the mean, variance and standard deviation for the following distribution.

Calculate the mean deviation from the median of the following data

The marks obtained (out of 100) by two students A and B in 10 qualifying tests  were:

who is more consistent in performance and who is more variable?

The mean and standard deviation of marks obtained by 50 students of a class in three subjects, Mathematics, physics and chemistry are given below:

Which of the three subjects shows the highest variability in marks and which shows the lowest?