If the mean and standard deviation of 5 observations `x_1, x_2, x_3, x_4, x_5` are 10 and 3 respectively, then the variance of 6 observations `x_1, x_2, x_3, x_4,x_5` and 50 is equal to

The mean and standard deviation of five observations x_(1),x_(2),x_(3),x_(4),x_(5) and are 10 and 3 respectively,then variance of the observation x_(1),x_(2),x_(3),x_(4),x_(5),-50 is equal to (a) 437.5 (b) 507.5 (c) 537.5 (d) 487.5

If, s is the standard deviation of the observations x_(1),x_(2),x_(3),x_(4) and x_(5) then the standard deviation of the observations kx_(1),kx_(2),kx_(3),kx_(4) and kx_(5) is

If the mean and standard deviation of 10 observations x_(1),x_(2),......,x_(10) are 2 and 3 respectively,then the mean of (x_(1)+1)^(2),(x_(2)+1)^(2),....,(x_(10)+1)^(2) is equal to

The mean and standard deviation of 10 observations x_(1), x_(2), x_(3)…….x_(10) are barx and sigma respectively. Let 10 is added to x_(1),x_(2)…..x_(9) and 90 is substracted from x_(10) . If still, the standard deviation is the same, then x_(10)-barx is equal to

The mean and variance of the 4 observations 3,7,x,y ("where" x gt y) is 5 and 10 respectively . the mean of the observation 4+x+y , 7+x , x+y , x-y will be

If both the mean and the standard deviation of 50 observations x_(1), x_(2),…, x_(50) are equal to 16, then the mean of (x_(1) -4)^(2), (x_(2) -4)^(2), …., (x_(50) - 4)^(2) is k. The value of (k)/(80) is _______.