a.
is a joint density function if its integral over the given support is 1:


so the answer is yes.
b. We should first find the density of the marginal distribution,
:


Then

or about 0.2019.
For the other probability, we can use the joint PDF directly:

which is about 0.7326.
c. We already know the PDF for
, so we just integrate:
![E[Y]=\displaystyle\int_{-\infty}^\infty y\,f_Y(y)\,\mathrm dy=\frac15\int_0^\infty ye^{-y/5}\,\mathrm dy=\boxed5](https://tex.z-dn.net/?f=E%5BY%5D%3D%5Cdisplaystyle%5Cint_%7B-%5Cinfty%7D%5E%5Cinfty%20y%5C%2Cf_Y%28y%29%5C%2C%5Cmathrm%20dy%3D%5Cfrac15%5Cint_0%5E%5Cinfty%20ye%5E%7B-y%2F5%7D%5C%2C%5Cmathrm%20dy%3D%5Cboxed5)
Answer:
6^2 is the answer
Step-by-step explanation:
just trust me ik
Answer:
None of the equations given is the equation of the function. The correct equation is: 
Step-by-step explanation:
First we must find the slope of the line that passes through these points.
The slope between two points
and
is given by:

where
is the slope
In this case since we have the points:
and 

and the slope will be:

and now we have the slope we use the slope-point equation:


Answer:
300 in2
Step-by-step explanation:
area of 2 identical triangle + area of 3 rectangle = surface area
(5*12/2)*2 + 8*12 + 5*8 + 8*13 = 300 in2
<span>4000 so the answer is C
Hope this helps</span>