<span>Answer: Where:
θ = confidence value
n = number of observations
μ = mean
Θ = standard deviation
... then your interval will be:
μ - θΘ/√n ≤ X ≤ μ - θΘ/√n
For some reason they want you to calculate the standard error, which is the Θ/√n section, and I mentioned the 1.96 value, so the above equation simplifies to: μ - 1.96SE ≤ X ≤ μ - 1.96SE</span>
Answer:
![\displaystyle [-7, -7]](https://tex.z-dn.net/?f=%5Cdisplaystyle%20%5B-7%2C%20-7%5D)
Step-by-step explanation:
{2x - 6y = 28
{−x - y = 14
−⅙[2x - 6y = 28]
{−⅓x + y = −4⅔
{−x - y = 14
____________

[Plug this back into both equations above to get the y-coordinate of −7]; 
I am joyous to assist you anytime.
Answer:
A. 25%
Step-by-step explanation:
If you multiply something by 0.75, you're multiplying it by 75%, and that means you're losing 25% each time, so the rate of decay is 25%
2x + y = 3
x = 2y - 1
solve for y in the first equation;
2x + y = 3
y = 3 - 2x
x = 2y - 1
x = 2(3 - 2x) - 1
x = -4x + 5
solve for x;
x = -4x + 5
x + 4x = 5
5x = 5
x = 1
solve for y;
y = 3 - 2x
y = 3 - 2(1)
y = 1
the answer is: x = 1, y = 1
hope this helps, God bless!
Since we want it in the form: (x - a)², let's first expand (x - a)² and then equate for the coefficients.
(x - a)² = x² - 2ax + a²
x² + 4x - 15 = x² - 2ax + a²
Now, let's focus on the middle term.
4x = -2ax
4 = -2a
a = -2
Thus, we know that a = -2
Then, we can say (x + 2)² = x² + 4x - 15
x² + 4x + 4 = x² + 4x - 15
Thus, 19 units are needed in order to complete the square to produce:
(x + 2)²