The Eco Pulse survey from the marketing communications firm Shelton Group asked individuals to indicate things they do that make them feel guilty (Los Angeles Times, August 15, 2012). Based on the survey results, there is a 0.39 probability that a randomly selected person will feel guilty about wasting food and a 0.27 probability that a randomly selected person will feel guilty about leaving lights on when not in a room. Moreover, there is a 0.12 probability that a randomly selected person will feel guilty for both of these reasons. Required:
a. What is the probability that a randomly selected person will feel guilty for either wasting food or leaving lights on when not in a room or both (to 2 decimals)?
b. What is the probability that a randomly selected person will not feel guilty for either of these reasons (to 2 decimals)?

a) 0.54 = 54% probability that a randomly selected person will feel guilty for either wasting food or leaving lights on when not in a room or both.

b) 0.46 = 46% probability that a randomly selected person will not feel guilty for either of these reasons

Step-by-step explanation:

We use Venn's Equations for probabilities.

I am going to say that:

P(A) is the probability that a randomly selected person will feel guilty about wasting food.

P(B) is the probability that a randomly selected person will feel guilty about leaving lights on when not in a room.

0.12 probability that a randomly selected person will feel guilty for both of these reasons.

This means that

0.27 probability that a randomly selected person will feel guilty about leaving lights on when not in a room.

This means that

0.39 probability that a randomly selected person will feel guilty about wasting food

This means that

a. What is the probability that a randomly selected person will feel guilty for either wasting food or leaving lights on when not in a room or both (to 2 decimals)?

0.54 = 54% probability that a randomly selected person will feel guilty for either wasting food or leaving lights on when not in a room or both.

b. What is the probability that a randomly selected person will not feel guilty for either of these reasons (to 2 decimals)?

0.46 = 46% probability that a randomly selected person will not feel guilty for either of these reasons

there are lots of ways.   pick's theorem tells us if the vertices are lattice points the area a is

a = b/2 + i - 1

where b is the number of boundary lattice points and i is the number of interior lattice points.

in the figure i count b=16, i=50 so

a = 8 + 50 - 1 = 57

let's try the shoelace formula.   the area is half the sum of the cross products of the sides.  

a(-2,6)   -2(2)-6(-5) = 26

b(-5,2)   -5(-3) - 2(-2) = 19

c(-2,-3) -2(-3) - (-3)(4) = 18

d(4,-3)   4(3) - (-3)(5) = 27

e(5,3)   5(3) - 3(1) = 12

f(1,3)     1(6) - 3(-2) = 12

a(-2,6)

each of the cross products is twice the area of the triangle with the associated side and one vertex the origin. so the area of abo=26/2=13.

area = (1/2) (26 + 19 +   18 + 27 + 12 + 12) = 57

that checks!

no not all of them.

step-by-step explanation:

some of them have a square base.