If mean of squares of deviations of a set of `n` observations about `-2a n d2` are 18 and 10 respectively then standard deviation of this set of observations is 3 (b) 2 (c) 1 (d) None of these

If mean of squares of deviations of a set of n observations about - 2 and 2 are 18 and 10 respectively,then standard deviation of this set of observations is

If mean of squares of deviations of a set of n observations about -2 and 2 are 18 and 10 respectively then standard deviation of this set of observations is 3 (b) 2 (c) 1 (d) None of these

If standard deviation of a set of observation is 4 and if each of the observations is divided by 4, then the standard deviation of new set of observations is

The mean and standard deviation of a set of n_1, observations are bar x_1 and s_1 ,respectively while the mean and standard deviation of another set of n_2 observations are bar x_2 and s_2, respectively. Show that the standard deviation of thecombined set of (n_1 + n_2) observations is given by S.D.=sqrt((n_1(s_1)^2+n_2(s_2)^2)/(n_1+n_2)+(n_1 n_2(( bar x )_1-( bar x )_2)^2)/((n_1+n_2)^2))

Show that the sum of deviations of a set of observations about their mean is Zero.

The mean and standard deviation of a set of n_1 observation are barx_1 and S_1 , respectively while the mean standard deviation of another set of n_2 observations are barx_2 and S_2 , respectively . Show that the standard deviation of the combined set of (n_1+n_2) observations is given by standard deviation sqrt ((n_1(S_1)^2 + n_1(S_2)^2)/(n_1+n_2) + (n_1+n_2 (barx_1 - barx_2)^2)/(n_1-n_2)^2)