A story about the doubles plus 2 fact 5+7

Consumer Reports uses a 100-point customer satisfaction score to rate the nations major chain stores. Assume that from the past

zzz [600]

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 $X-\bar{X}$ $(X-\bar{X})^2$

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 = $\frac{\textup{Sum of all observations}}{\textup{Total number of observations}}$

or

Mean = $\frac{\textup{1260}}{\textup{15}}$ = 84

(B) Variance = $\frac{\sum(X-\bar{X})^2}{n-1}$

or

Variance = $\frac{1662}{15-1}$

or

Variance = 118.714

(C) Standard deviation = √Variance = √118.714 = 10.89

7 0

3 years ago

PLEASE ANSWER QUICKLY

sammy [17]

By applying the definition of product between two <em>square</em> matrices, we find that $\vec A \,\cdot \,\vec A = \left[\begin{array}{cc}1&2\\3&6\end{array}\right] \cdot \left[\begin{array}{cc}1&2\\3&6\end{array}\right]$ is equal to the matrix $\vec A \,\cdot \,\vec A = \left[\begin{array}{cc}7&14\\21&42\end{array}\right]$ . (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:

$\vec A \,\cdot \,\vec A = \left[\begin{array}{cc}1&2\\3&6\end{array}\right] \cdot \left[\begin{array}{cc}1&2\\3&6\end{array}\right]$

$\vec A \,\cdot \,\vec A = \left[\begin{array}{cc}7&14\\21&42\end{array}\right]$

By applying the definition of product between two <em>square</em> matrices, we find that $\vec A \,\cdot \,\vec A = \left[\begin{array}{cc}1&2\\3&6\end{array}\right] \cdot \left[\begin{array}{cc}1&2\\3&6\end{array}\right]$ is equal to the matrix $\vec A \,\cdot \,\vec A = \left[\begin{array}{cc}7&14\\21&42\end{array}\right]$ .

To learn more on matrices: brainly.com/question/11367104

#SPJ1

6 0

2 years ago

Draw and label a figure for each relationship.<br> Points X and Y lie on CD.

gavmur [86]

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

#SPJ1