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2 years ago

This is due today can anyone help ?

Mathematics

1 answer:

Lorico [155]2 years ago

7 0

Answer:

Step-by-step explanation:

you need to start by plugging in -2x+4 every were it says y then solve for x when you have found x plug it into one of the equations and solve for y

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An architect planned to construct two similar stone pyramid structures in a

Vinil7 [7]

Answer:

C. Change the length to side CB to 8 feet

Step-by-step explanation:

<u>Corresponding sides of similar triangles should have same ratio:</u>

PR/AC = PQ/AB = RQ/CB
7.5/6 = 5/4 = 10/CB
10/CB = 1.25
CB = 10/1.25
CB = 8 feet

Correct choice is C

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2 years ago

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What is the slope for a line that goes through the points and (14, -3) and (10, 4)?

garri49 [273]

The slope for the line would be a triangle

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Five observations taken for two variables follow.

I am Lyosha [343]

Answer:

a) Figure attached

b) If we see the scatter plot we can conclude that the possible relation between x and y is linear and with a positive correlation since when the values of x increases the values for y increases as well.

c) $Cov (X,Y) = \frac{\sum_{i=1}^n (x_i -\bar X)(y_i -\bar Y)}{n-1}$

We can find the numerator like this:

$\sum_{i=1}^5 (6-16)(6-10)+(11-16)(9-10)+(15-16)(6-10)+(21-16)(17-10)+(27-16)(12-10)=106$

And then:

$Cov(X,Y) = \frac{106}{5-1}=26.5$

d) $r=\frac{5(906)-(80)(50)}{\sqrt{[5(1552) -(80)^2][5(586) -(50)^2]}}=0.693$

Step-by-step explanation:

Part a

For this part we use excel in order to create the scatterplot and we got the result on the figure attached.

Part b

If we see the scatter plot we can conclude that the possible relation between x and y is linear and with a positive correlation since when the values of x increases the values for y increases as well.

Part c

The sample covariance is defined as:

$Cov (X,Y) = \frac{\sum_{i=1}^n (x_i -\bar X)(y_i -\bar Y)}{n-1}$

We can find the numerator like this:

$\sum_{i=1}^5 (6-16)(6-10)+(11-16)(9-10)+(15-16)(6-10)+(21-16)(17-10)+(27-16)(12-10)=106$

And then:

$Cov(X,Y) = \frac{106}{5-1}=26.5$

Part d

The correlation coefficient is a "statistical measure that calculates the strength of the relationship between the relative movements of two variables". It's denoted by r and its always between -1 and 1.

And in order to calculate the correlation coefficient we can use this formula:

$r=\frac{n(\sum xy)-(\sum x)(\sum y)}{\sqrt{[n\sum x^2 -(\sum x)^2][n\sum y^2 -(\sum y)^2]}}$