Air has a density of 0.0013 g/cm3.  What is the mass of air contained
in a room with the dimensions of 11.0 ft. X 19.0ft. X 8.0?

Is the correct answer 857438.460?

I will assume that the last dimension of the room is 8.0 ft.
The next thing that we must know is in wich units do you want the mass
of the air, grams or pounds.
I will calculate the mass in grams.
D: density, M: mass, V: volume.
D = M/V , then M = D x V (multiplying both sides of the equation by
V).
Now we must to pay attention to the units, to make a calculation we
have to work with the same set of units. So the next step is to
convert the dimensions of the room in cm in order to obtain the volume
in cm3 (because we have the unit of density is g/cm3 we need to know
the volume in cm3 not ft3).
1ft = 30.48cm then 11ft = 335.28cm, 19ft = 579.12cm and 8ft =
243.84cm.
Then the volume of the room is:
V = 335.28cm * 579.12cm x 243.84cm = 47345767,5cm3
Now we replace in the equation M = D x V
M = 0.0013 g/cm3 x 47345767,5cm3 = 61549,5 grams.

Hope this helps.

That is not the answer I got.  You did not include any units for your
answer.  There is very important, especially if you are dealing with
different measuring systems.  Also, you have too many significant
digits.

Post another answer, showing your work, and I will tell you if it is
correct.

2.54 cm / in, 12 in / ft

V = h x w x d

Dear shelbyarps,

Is the correct answer 857438.460?

No, for two reasons:

(1) Your answer is a number, not a mass.  A mass is expressed as a
number multiplied by an appropriate unit.

(2) The values in the question are given to two or three significant
figures.  In a calculation like this, the result cannot be any more
significant than the values in the question, so the answer should also
be given to two significant figures, but your answer claims to be
given to at least eight significant figures.

Carnegie

The formula you need to know for this question and your previous ones
is:

Mass = density x volume

Two additional points:

(1) Make sure you are working with the same measurement units. So if
mass units are given in g and lbs, convert the latter to g. If
distance units are given in cm and ft, convert the latter to cm.
Metric is the best way to go in science.

(2) Make sure you understand significant digits (s.d.). A density of
0.0013 g/cm3 has 2 s.d. Measurements of 11.0 ft and 19.0 ft have 3
s.d., while 8.0 ft has 2 s.d. Thus, the answer provided by
livioflores-ga, provided the numbers are correct (I didn't bother
calculating them), should have 2 s.d., properly expressed in
scientific notation as 6.1 x 10^4 g.

I strongly recommend asking your chemistry teacher for more
information or consulting an introductory science or chemistry
textbook.