Question

6. (10 points total) An insurance policy pays $1000 per day for up to 3 days of hospitalization and$500 per day for each day of hospitalization thereafter. The number of days of hospitalization,X, is a discrete random variable with probability function

p_{X}(k)=\left\{\begin{array}{cc} \frac{6-k}{15} & \text { for } k=1,2,3,4,5 \\ 0 & \text { otherwise } \end{array}\right.

(a) (5 points) Determine the expected payment for hospitalization under this policy.

(b) (5 points) Determine the variance of the payment for hospitalization under this policy.

Verified

### Question 44046

During the summer months, British Columbia experiences numerous forest fires. You are working as a fire ranger in the interior of British Columbia and you spot a fire that is 15 km away from your tower. Your friend is working at another tower that is located 20 km from you at an angle of 21°. She can also see the fire.
b) Your friend decides to dispatch a water plane to the fire. Your station is not equipped with waterplanes. At what angle should the plane fly to target the fire accurately? (AP3)
Your friend decides to dispatch a water plane to the fire. Your station is not equipped with water planes. At what angle should the plane fly to target the fire accurately? (AP3)

### Question 44045

As a computer engineer, you are always looking at ways to improve the computing experience. As part of your final paper to submit for your Master's Degree, you do some research about how far computing has come over the years.
You make some interesting discoveries. Dating back to 1940, you find out that one of the original large computers was able to perform about 100 operations per second. After examining the data,you see that the speed of computers has multiplied 5-fold about every 7 years.
a) Some of the data is missing. You know that some super computers can now process4 882 812 500 operations per second. How many years have gone by to reach this number of operations? What year would this have occurred in? Show your solution algebraically! (AP5)
b) Do you think this is a realistic model? What limitation(s) may arise with this model? (CM3)

### Question 43374

Find the distance between the parallel planes P: 5x - 3y + z=1 and P: 10x-6y +2z=4. Enter an exact answer, do not use decimal approximation.

### Question 43373

Find an equation for the plane through the point (3, 2,-5) and parallel to the plane defined by5x- 4y + 4z = 12.
1=5(x-3)-4(y+5)+10(z-2)
0=-4(x+3)+5(y-2)+4(z+5)
1=5(x-3)-4(y-2)+4(z+5)
0=5(x-3)-4(y-2)+4(z+5)

### Question 43372

\text { Find the plane containing the three points } P(3,-2,1), Q(1,-3,0) \text { and } R(3,-5,5) \text {. }
0=-7(x+3)+8(y-2)+6(z+1)
0=-7(x-3)+8(y+2)+6(z-1)
0=-7(x-3)-8(y+2)+6(z-1)
1=-7(x-3)+8(y+2)+6(z-1)

### Question 43371

Find the directions of maximum and minimum change of f at the given point, and the values of the maximum and minimum rates of change.
f(x, y)=5 y^{2} e^{7 x},(4,-3)
\text { The maximum change is } 15 e^{28} \sqrt{445} ; \text { in the direction }\left(-315 e^{28}, 30 e^{28}\right)
\text { The minimum change is }-15 e^{28} \sqrt{445} ; \text { in the direction }\left(315 e^{28},-30 e^{28}\right) \text {. }
\text { The maximum change is } 15 e^{-28} \sqrt{445} ; \text { in the direction }\left(-315 e^{-28}, 30 e^{-28}\right)
\text { The minimum change is }-15 e^{-28} \sqrt{445} ; \text { in the direction }\left(315 e^{-28},-30 e^{-28}\right)
\text { The maximum change is } 15 e^{28} \sqrt{445} ; \text { in the direction }\left(315 e^{28},-30 e^{28}\right\rangle
\text { The minimum change is }-15 e^{28} \sqrt{445} ; \text { in the direction }\left\{-315 e^{28}, 30 e^{28}\right)
\text { The maximum change is } 15 e^{-28} \sqrt{445} ; \text { in the direction }\left(315 e^{-28},-30 e^{-28}\right)
\text { The minimum change is }-15 e^{-28} \sqrt{445} \text {; in the direction }\left(-315 e^{-28}, 30 e^{-28}\right\rangle

### Question 43370

Select the description and the sketch of the domain of the function.
f(x, y)=\frac{4 x y}{\left(y-x^{2}\right)}

### Question 43369

\text { Find an equation of the line passing through the points } P(3,4,-2) \text { and } Q(5,-4,3) \text {. }
\frac{x+3}{2}=\frac{y+4}{-8}=\frac{z-2}{5}
\frac{x+4}{-4}=\frac{y+4}{5}=\frac{z-3}{3}
\frac{x-3}{2}=\frac{y-4}{-8}=\frac{z+2}{5}
x-3=y-4=z+2

### Question 43368

Round each component to four decimal places, if necessary.
\text { Find the gradient of } f(x, y)=3 e^{5 x d y}+2 x \text { at }(-1,-1)
\nabla f(-1,-1) \approx

### Question 43367

\text { Find the gradient of the function } f(x, y)=x^{2}+4 x y^{2}-y^{7}