If the values observed are `1,2,…..,n` each with frequency 1, find the mean value

Suppose the values x_1, x_2,…..x_n having frequency f_1, f_2…...f_n respectively have mean value overset- x and variation sigma^2 .Let a be a fixed real number. Show that the values x_1+a,x_2+a,….,x_n+a with frequency f_1,f_2….f_n respectively will have mean value overset-x+a and variance sigma

Let x_1,x_2…x_n be a set of observations with mean value 0 and variance sigma_x^2 and y_1,y_2,…,y_m be another set of observations with mean value 0 and variance… Find the mean value and variance of the set of observations x_1,x_2,,,,x_n, y_1,y_2,…y_m combined.

From the table below, find the mean value and the variance.

If the points (-1,-1,2), (2,m,5) and (3,11,6) are collinear, then find the value of m.

The coefficient of variation is defined as sigma//overset-x that is the standard deviation divided by the mean value. Find the coefficient of variation c.v. for each of the following set of observations. 2,3,4,2,5,7,8,9

Give the values of 'n' and 'l' for each of the subshell :

Find the value of cos 1^@, cos 2^@ ….. Cos 100^@

From the tables below, find the mean and the variance. Values: 1 3 5 …….(2n-1) Frequency: 1 1 1…….. 1