Processing math: 100%
 
  Questions   
Sort: 
 #1
avatar+2446 
+3

I think the best thing to do here is to construct a diagram. The problem gives you vertices with coordinates from the Cartesian plane, and it even gives you an inequality. Here is the construction I created. I will reference it throughout the solving process:

 

 

I first located the given coordinates and connected them with vertical and horizontal lines. I then graphed the inequalityx>7y, which can be rewritten as y<x7 . I added a few points, as they will become relevant when I solve.

 

One way to solve this problem is to figure out the ratio of the area created by the inequality y<x7 and the sides of the rectangle to the area of the entire rectangle. I will do this by first finding the coordinates of the point E. Point E is located on ¯BC , so its x-coordinate is also 2009. If you know the x-coordinate, then the y-coordinate of any point on y=x7 is x7 . Therefore, the y-coordinate is 20097

 

The formula for the area of the triangle is 12bhABE is a right triangle, so the base and height are the side lengths that are not the hypotenuse. We know the length of the base, AB , because it is in the diagram. The height is the length of BE , or 20097

 

A=12ABBE=12200920097=2009214

 

We can also calculate the area of the rectangle

 

Arect.=bh=ABBC=20092010

 

As aforementioned, the probability of (x,y) such that x>7y is just the ratio of these areas.

 

P(x,y|x>7y)=AArect. As aforementioned, the probability of (x,y) such that x>7y is just the ratio of these areas. Substitute in the values and simplify.
P(x,y|x>7y)=200921420092010 Use algebraic manipulation to simplify this.
P(x,y|x>7y)=200921420092010  
P(x,y|x>7y)=2009142010 At this point, you must use a calculator. 
P(x,y|x>7y)=0.07139  
   


 

 #3
avatar+33654 
+5
Dec 8, 2018
 #4
avatar+50 
+1
Dec 8, 2018

0 Online Users