'be approximately equal to' is correct and usable in written English.
You can use it when you want to express that two things are almost the same, but not exactly. For example, "The two numbers were approximately equal to each other."
One concern for the I.M.F. may be whether Cyprus would ever be able to pay back loans that would be approximately equal to its entire gross domestic product.
The reciprocity of the cycle rests in the obligation to return the gift; the prestige associated with the appearance of generosity dictates that the value of the return be approximately equal to or greater than the value of the original gift.
Therefore, standard deviation is checked (it must be approximately equal to 0).
The Tafel slope was found to be approximately equal to 2.3 RT/F and independent of electrolyte concentration.
Shape of colloidal quantum dots should be close to spherical (width of quantum dot should be approximately equal to height).
To investigate this relation, the injection flow rate should be considered to be approximately equal to the droplet flow rate.
The running subtraction estimate is shown to be approximately equal to a temporally low-pass-filtered version of the least-squares estimate.
Secondly, the CO2 allowances purchased from the CO2 allowance market should be approximately equal to the quantity of CO2 emission from power generation.
The number of missed pedestrians has to be approximately equal to 0 since a pedestrian missed by the ROI selection stage would not be detected in further stages.
In this design the typical distance between two simultaneously active inlet and outlet ports will be approximately equal to twice the axial dispersion length.
Moreover, the normalized elastic buckling strength of a hexagonal honeycomb with dual imperfections is found to be approximately equal to the product of that with each single imperfection.
