The phrase "approximately half that of" is grammatically correct and commonly used in written English.
It is typically used to compare two quantities or measurements. Example: "The cost of living in New York City is approximately half that of San Francisco."
Ungulates accounted for only 35% of prey items in one survey, approximately half that of North America.
The salinity of the surface waters in the open sea averages between 17 and 18 parts per thousand, which is approximately half that of the oceans.
For the two-dimensional plume, the rate of entrainment with respect to height of rise is approximately half that of an equivalent two-dimensional balcony spill plume.
The thermal conductivity for a grain size of 10 nm is reduced to approximately half that of coarse-grained or single-crystal material at all measured temperatures.
The average nanotip size is 26 ± 8 nm, which is approximately half that of the Si-based nanotips shown in Figure 1b.
At the lower temperature of 140 K, pore-free carbon dioxide ice has also been measured to have a specific cutting strength approximately half that of water ice at the same temperature.
Six days post-infection, the growth of intracellular M.tb in SD-treated THP-1-derived macrophages was only approximately half that of the control THP-1 cells (Fig. 2a).
Effective template concentration at a heterozygous locus is approximately half that of a homozygous locus, therefore less than optimal sample concentration can lead to incomplete genotyping of heterozygous individuals.
The life span of horses on Cumberland Island is approximately half that of their ancestors, due to infestations of parasites and disease.
Additionally, the cytoplasm of the non-culturable cells has condensed into a small rounded cytosol with a volume of approximately half that of the laboratory grown cells.
Figure 7 shows that expression levels of Csrp2bp and 6330439K17Rik in PPCD1 eyes at 28 days are approximately half that of wild-type.
