Answer:
12 the answer is 12
Step-by-step explanation:
Answer:
a. 0.8366
b. No
Step-by-step explanation:
We will use the central limit theorem which can be applied to a random sample from any distribution as long as the mean and the variance are both finite and the sample size is large (the sample size n should be greater than 30). Here we have that the tip percentage at the restaurant has a mean value of 18% and a standard deviation of 6%, then because of the central limit theorem, we know that the sample mean tip percentage is approximately normally distributed with mean 18% and standard deviation
.
a. The z-score related to 16% is given by (16-18)/0.9487 = -2.1081 and the z-score related to 19% is given by (19-18)/0.9487 = 1.0541. We are looking for
b. If the sample size had been 15 rather than 40, then, the probability requested in part (a) could not be calculated from the given information, this because the central limit theorem only applies when the sample size is large, for example n > 30.
Using the discriminant, the quadratic equation that has complex solutions is given by:
x² + 2x + 5 = 0.
<h3>What is the discriminant of a quadratic equation and how does it influence the solutions?</h3>
A quadratic equation is modeled by:
y = ax² + bx + c
The discriminant is:

The solutions are as follows:
- If
, it has 2 real solutions.
- If
, it has 1 real solutions.
- If
, it has 2 complex solutions.
In this problem, we want a negative discriminant, hence the equation is:
x² + 2x + 5 = 0.
As the coefficients are a = 1, b = 2, c = 5, hence:

More can be learned about the discriminant of quadratic functions at brainly.com/question/19776811
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Answer:
Step-by-step explanation:
-2x + 3y – 4z = 8 ----------------(I)
5x – 3y + 5z = -8 -----------------(II)
7x – 3y + 3z = 8 ------------------(III)
Add equation (I) & (II) and thus y will be eliminated
(I) -2x + 3y – 4z = 8
(II) <u>5x – 3y + 5z = -8</u> {Add}
3x + z = 0 ------------------------(A)
Multiply equation (II) by (-1) and then add with equation (III). Thus y will be eliminated.
(II) * (-1) -5x + 3y - 5z = +8
<u>7x – 3y + 3z = 8</u> {Add}
2x -2z = 16 ---------------(B)
Multiply equation (A) by 2 and then add. Thus z will be eliminated and we will get the value of x
(A) * 2 6x + 2z = 0
(B) <u>2x - 2z = 16</u> {Add}
8x = 16
Divide both sides by 8
x = 16/8
x = 2
Plugin x = 2 in equation (A)
3x + z = 0
3*2 + z = 0
6 + z = 0
z = -6
Plug in x = 2 and z = - 6 in equation (I)
-2x +3y - 4z = 8
-2*2 + 3y - 4*(-6) = 8
-4 + 3y + 24 = 8
3y + 20 = 8
3y = 8 - 20
3y = -12
y = -12/3
y = -4
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Add together your portions 1 + 3 + 5 = 9
divide 72 by 9 = 8
Each portion is multiplied by 8
1 x 8 = 8
3 x 8 = 24
5 x 8 = 40
Your portions are 8kg:24kg:40kg
Is this correct? Add 8 + 24 + 40. Do they equal 72? yes. Your portions are correct.