When statisticians describe pooling the variances, they mean: taking the average of the two variances disregarding sample size. adding the variances of the two samples. taking the average of the two variances accounting for sample size. adding the standard deviations of the two samples.

Which of the following statements about imprisonment rates in the united states is true? the united states imprisons people at a higher rate than russia, mexico, or canada. the united states imprisons people at a lower rate than russia or south africa, but higher than israel. the united states imprisons people at a lower rate than russia, mexico, or canada. russia, south africa, and mexico each imprison more people than the united states.