Looks like you have most of the details already, but you're missing one crucial piece.
is parameterized by

for
and
, and a normal vector to this surface is

with norm

So the integral of
is

There are 16 smaller triangles within the main large one. .25=1/4, so your fraction is 1/4. 1/4 of 16 is 4, because 4+4+4+4=16. So colour in 4 triangles. Hope this helps!
6. Often, judging the symmetry and skewness of such distributions is not easy to do by eye, especially when they are asymmetrical or skewed in different ways. Here, the mean of set A is about 7, so the data is skewed to the left more than for set B, which has a mean of about 5.4--closer to the middle of the range.
Both data sets have the same range: 2–10. Set A's mode of 8 is higher than set B's mode of 6.
Hence, the only true statement appears to be
... B. Set B has the lesser mean.
7. For each of the 3 choices of meat, there are 3 choices of bread, and for each of any of those 9 choices, there are 4 choices of condiment—a total of 3×3×4 = 36 choices in all. The best answer is ...
... C. 36
8. The pie chart tells you 5% of the $4800 of monthly income is spent on transportation. That amount is .05×$4800 = ...
... C. $240
If I understand correctly, you went wrong because you solved for Y instead of M, like the question dictates.
Answer:
243
Step-by-step explanation:
3*3*3*3*3=243