Quadrant Four (IV) since the x coordinate is a positive and the y coordinate is a negative.
Answer:
Step-by-step explanation:
Given that the random variable X is normally distributed, with
mean = 50 and standard deviation = 7.
Then we have z= 
Using this and normal table we find that
a) 
b) When z=0.02
we get
c) 90th percentile z value =1.645
90th percentile of X 
To solve, we will follow the steps below:
3x+y=11 --------------------------(1)
5x-y=21 ------------------------------(2)
since y have the same coefficient, we can eliminate it directly by adding equation (1) and (2)
adding equation (1) and (2) will result;
8x =32
divide both-side of the equation by 8
x = 4
We move on to eliminate x and then solve for y
To eliminate x, we have to make sure the coefficient of the two equations are the same.
We can achieve this by multiplying through equation (1) by 5 and equation (2) by 3
The result will be;
15x + 5y = 55 ----------------------------(3)
15x - 3y =63 --------------------------------(4)
subtract equation (4) from equation(3)
8y = -8
divide both-side of the equation by 8
y = -1
