singular or plural verb?

[trapanipalermo]

Hi guys,
could you please tell me which sentence is correct?

their mass density is 0.675, 0.660 and 0.670 g/cm3, respectively

or
their mass densities are 0.675, 0.660 and 0.670 g/cm3, respectively

thanks a lot
Patrizio

 

[David L.]

their mass densities are 0.675, 0.660 and 0.670 g/cm3 respectively

 

[banderas]

Hi guys,
could you please tell me which sentence is correct?

their mass density is 0.675, 0.660 and 0.670 g/cm3, respectively

or
their mass densities are 0.675, 0.660 and 0.670 g/cm3, respectively

thanks a lot
Patrizio

The values of X, Y and Z were found to be ..., .... and ....., respectively.

I think, you've got to name all of them (like the mass density of X, Y and Z) to be able to finsish the sentence with "respectively"

This is my suggestion but see what others say;-)

 

[David L.]

It is taken for granted that X,Y,and Z have been defined in the preceding sentence, by the use of the impersonal pronoun "their', which refers back to them.