Answer:
(A) Mean = 84
(B) Variance = 118.714
(C) Standard deviation = 10.89
Step-by-step explanation:
Data provided:
number of observations, n = 15
sample of 15 costco customer satisfaction scores follow
X

95 11 121
90 6 36
83 -1 1
64 -20 400
95 11 121
98 14 196
80 -4 16
83 -1 1
82 -2 4
93 9 81
86 2 4
80 -4 16
94 10 100
75 -9 81
62 -22 484
================================================
∑X = 1260 ∑= 1662
Now,
(A) Mean = 
or
Mean =
= 84
(B) Variance = 
or
Variance = 
or
Variance = 118.714
(C) Standard deviation = √Variance = √118.714 = 10.89
By applying the definition of product between two <em>square</em> matrices, we find that
is equal to the matrix
. (Correct choice: D)
<h3>What is the product of two square matrices</h3>
In this question we must use the definition of product between two <em>square</em> matrices to determine the resulting construction:
![\vec A \,\cdot \,\vec A = \left[\begin{array}{cc}1&2\\3&6\end{array}\right] \cdot \left[\begin{array}{cc}1&2\\3&6\end{array}\right]](https://tex.z-dn.net/?f=%5Cvec%20A%20%5C%2C%5Ccdot%20%5C%2C%5Cvec%20A%20%3D%20%5Cleft%5B%5Cbegin%7Barray%7D%7Bcc%7D1%262%5C%5C3%266%5Cend%7Barray%7D%5Cright%5D%20%5Ccdot%20%5Cleft%5B%5Cbegin%7Barray%7D%7Bcc%7D1%262%5C%5C3%266%5Cend%7Barray%7D%5Cright%5D)
![\vec A \,\cdot \,\vec A = \left[\begin{array}{cc}7&14\\21&42\end{array}\right]](https://tex.z-dn.net/?f=%5Cvec%20A%20%5C%2C%5Ccdot%20%5C%2C%5Cvec%20A%20%3D%20%5Cleft%5B%5Cbegin%7Barray%7D%7Bcc%7D7%2614%5C%5C21%2642%5Cend%7Barray%7D%5Cright%5D)
By applying the definition of product between two <em>square</em> matrices, we find that
is equal to the matrix
.
To learn more on matrices: brainly.com/question/11367104
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A number line was used to draw and label a figure for Points X and Y that lies on CD as shown in the image attached below.
<h3>What is a line segment?</h3>
A line segment can be defined as the part of a line in a geometric figure such as a triangle, circle, quadrilateral, etc., that is bounded by two (2) distinct points and it typically has a fixed length.
<h3>What is a number line?</h3>
A number line can be defined as a type of graph with a graduated straight line which contains numerical values (positive and negative numbers) that are placed at equal intervals along its length.
A number line would be used to draw and label a figure for Points X and Y that lies on CD as shown in the image attached below.
Read more on collinear points and segment here: brainly.com/question/3307641
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Answer:
5 doallar an hour
Step-by-step explanation:
adddasdda
Y4 - y3 + 2y2 + y - 1 over (y + 1) • (y2 - y + 1)
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