The phrase "proportion at which" is correct and can be used in written English.
This phrase is used to indicate the extent or degree to which something is done. For example, "We need to consider the proportion at which we increase production in order to meet customer demand".
We also supplement this graphical/visual assessment by calculating the proportion at which a given variable is present or absent.
This product is equivalent to the proportion at which a variable is both selected in the final model and is significant using the validation data set.
Table 1 shows results from the bootstrapping approach in which covariates are ordered by the proportion at which they were selected in the final model following three commonly used selection procedures: forward, backward and stepwise.
What we are interested in is the probability of A & B. This probability, which incorporates stability and generalizability measures, can be estimated as the proportion at which a given variable is selected and is significant simultaneously.
With plausible combinations of these factors, a virus that requires three mutations reaches proportions at which a few respiratory droplet transmissible A/H5N1 viruses are likely to be among the particles excreted.
Taking in account the proportions at which they occur, the mean value of genotypes produced from the paternally-derived A1 allele is (1− q) a + qd1.
These results were all obtained using the published proportions at which E. coli biomass constituents [ 24] occur in the E. coli cell.
We investigated three Θ-regimes that differ in the relative proportions at which hard and soft sweeps arise during the large phases before they experience a bottleneck: (i) Mostly hard sweeps arise during the large phase (Θ = 0.2), (ii) mostly soft sweeps arise during the large phase (Θ = 2), and (iii) practically only soft sweeps arise during the large phase (Θ = 20).
The variables are then ordered according to their relative importance, where the importance of a variable is measured by the proportion (s) it is selected as a predictor and as well as the proportion (v) at which it is significant in the validation data set.
2002a); and two parameters related to energy allocation between growth and reproduction after maturation, that is the proportion α of energy devoted to somatic growth in the first adult year and the annual ratio χ at which this proportion decreases throughout adult life (Table 1; see section Life-history processes for more details).
For each individual, we evaluated the proportion of loci at which missing data occurred and the proportion of homozygotes among those loci for which data were not missing.
