The other assumptions are listed in the related link. The answer you are looking for is the same variance or standard deviation.
When data is homogeneous over k independent samples of size n_i for i=1,2,...,k, the pooled variance is given by s_p^2=((n_1-1) s_1^2+(n_2-1) s_2^2+⋯(n_k-1) s_k^2)/(n_1+n_2+⋯+n_k-k)
Favourable variance is that variance which is good for business while unfavourable variance is bad for business
There are 7 variances associated with a budget ( which are generally calculated for controlling purposes) 1- Material Price variance 2- Material Quantity variance 3- Labor rate variance 4- Labor efficiency variance 5- Spending variance 6- Efficiency variance 7- Capacity variance
Pooled variance is a method for estimating variance given several different samples taken in different circumstances where the mean may vary between samples but the true variance (equivalently, precision) is assumed to remain the same. A combined variance is a method for estimating variance from several samples, given the size, mean and standard deviation of each. Mathematically, a combined variance is equal to the calculated variance of the set of the data from all samples. See links.
Unequal in Variance
Investors care about mean and variance of returns only.They have homogeneous expectations.They have identical investment horizons.There is unlimited borrowing and lending at the risk-free rate.All assets are marketable.Unlimited short sales are allowed.Investors are price takers.There are no taxes and no transaction costs.Assets are perfectly divisible.
sole supliers no close subsstitutes homogeneous lack of knowldge of buyers
The other assumptions are listed in the related link. The answer you are looking for is the same variance or standard deviation.
When data is homogeneous over k independent samples of size n_i for i=1,2,...,k, the pooled variance is given by s_p^2=((n_1-1) s_1^2+(n_2-1) s_2^2+⋯(n_k-1) s_k^2)/(n_1+n_2+⋯+n_k-k)
Favourable variance is that variance which is good for business while unfavourable variance is bad for business
Negative price variance is when the cost is less than budgeted. Volume variance is a variance in the volume produce.
efficiency variance, spending variance, production volume variance, variable and fixed components
this is a technical term which is used for no firm and consumer can directly affect the market price. Assumptions are: large no's of buyers and sellers. price taker price minimum perfect information homogeneous product perfectly elastics free entry or exits no transportation cost.
There are 7 variances associated with a budget ( which are generally calculated for controlling purposes) 1- Material Price variance 2- Material Quantity variance 3- Labor rate variance 4- Labor efficiency variance 5- Spending variance 6- Efficiency variance 7- Capacity variance
Variance
Since Variance is the average of the squared distanced from the mean, Variance must be a non negative number.