Answer:
a. r=d/t b. 800000/4=200,000 c.800/2=200 d.not sure km are used more often as theyre simpler to use but there is not much that i am basing this off of
Step-by-step explanation:
Answer:
C. 31.83 feet.
Step-by-step explanation:
We have been given that Trina has $1000 to purchase an open-top cylindrical dog pen in her backyard. She wants the height of the pen to be 5 feet.
First of all, we will find the surface area of dog pen using surface area of cylinder.
,where,
r = Radius of cylinder,
h = Height of cylinder.


Since the area of each square foot of pen costs $1, so in $1000 Trina can cover an area of 1000 square feet.
Now, we will set the surface area of cylinder equal to 1000 to solve for the radius.

Upon dividing both sides of our equation by 10 pi we will get,



Therefore, the radius of the dog pen is 31.83 feet and option C is the correct choice.
Answer:
There are 31 students in the class.
Step-by-step explanation:
Looks like a badly encoded/decoded symbol. It's supposed to be a minus sign, so you're asked to find the expectation of 2<em>X </em>² - <em>Y</em>.
If you don't know how <em>X</em> or <em>Y</em> are distributed, but you know E[<em>X</em> ²] and E[<em>Y</em>], then it's as simple as distributing the expectation over the sum:
E[2<em>X </em>² - <em>Y</em>] = 2 E[<em>X </em>²] - E[<em>Y</em>]
Or, if you're given the expectation and variance of <em>X</em>, you have
Var[<em>X</em>] = E[<em>X</em> ²] - E[<em>X</em>]²
→ E[2<em>X </em>² - <em>Y</em>] = 2 (Var[<em>X</em>] + E[<em>X</em>]²) - E[<em>Y</em>]
Otherwise, you may be given the density function, or joint density, in which case you can determine the expectations by computing an integral or sum.
Answer:
3rd one
Step-by-step explanation: