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4 years ago

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At a movie, angelo bought a medium popcorn for $4, a small drink for $3, and a box of fruit snack for $5. write and solve a subt

raction equation to find how much money angelo gave the cashier if he received $3 in change.

1 answer:

Ksenya-84 [330]4 years ago

7 0

15-12=3. 4+5+3= 12. 12+3=15

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The number of motor vehicles registered in millions in the US has grown as follows:

zysi [14]

Answer:

a) Figure attached

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

For our case we have this:

n=10 $\sum x = 75.819, \sum y = 43.5231, \sum xy = 330.0321, \sum x^2 =574.8598, \sum y^2 =192.8274$

$r=\frac{10(330.0321)-(75.81948)(43.5231)}{\sqrt{[10(574.8598) -(75.819)^2][10(192.8274) -(43.5231)^2]}}=0.989$

So then the correlation coefficient would be r =0.989

Step-by-step explanation:

Previous concepts

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.

Solution to the problem

Part a

Year (x): 1940, 1945 1950, 1955, 1960, 1965, 1970, 1975, 1980, 1985

Vehicles (Y): 32.4, 31.0, 49.2, 62.7, 73.9, 90.4, 108.4, 132.9, 155.8, 171.7

After apply natural log for the two variables and create the scatterplot in excel we got the following result on the figure attached.

Part b

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

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

For our case we have this:

n=10 $\sum x = 75.819, \sum y = 43.5231, \sum xy = 330.0321, \sum x^2 =574.8598, \sum y^2 =192.8274$

$r=\frac{10(330.0321)-(75.81948)(43.5231)}{\sqrt{[10(574.8598) -(75.81948)^2][10(192.8274) -(43.5231)^2]}}=0.989$

So then the correlation coefficient would be r =0.989

4 0

3 years ago

What is the answer to -0.3x 2=0.4x-0.1

ch4aika [34]

That blank is a plus sign

ok so rememmber you can do anythiing to an equation as long as you do it to both sides

-0.3x+2=0.4x-0.1
add 0.3x to both sides
2=0.7x-0.1
add 0.1 to both sides
2.1=0.7x
times 7 both sides
21=7x
divide both sides by 7
3=x

7 0

3 years ago

What pattern do you see in the 10s count-bys?

Naya [18.7K]

Answer:

You add 10 each time.

6 0

3 years ago

Read 2 more answers

Which of the economic goals correlates with the explanation "the ability of people to make choices"?

valentinak56 [21]

<span>The correct answer is D, freedom. This is because equity only refers to everything being equal, innovation refers to the a new idea, and efficiency refers to being able to do something with ease. Only freedom makes sense in regards to people being able to make their own choices.</span>

4 0

4 years ago

0.3(4-x)=x-1.4 how do you solve this problem?

tresset_1 [31]

Answer:

x = 2.

Step-by-step explanation:

Solve for x:

0.3 (4 - x) = x - 1.4

Expand out terms of the left hand side:

1.2 - 0.3 x = x - 1.4

Subtract x from both sides:

1.2 + (-0.3 x - x) = (x - x) - 1.4

-0.3 x - x = -1.3 x:

-1.3 x + 1.2 = (x - x) - 1.4

x - x = 0:

1.2 - 1.3 x = -1.4

Subtract 1.2` from both sides:

(1.2 - 1.2) - 1.3 x = -1.2 - 1.4

1.2 - 1.2 = 0:

-1.3 x = -1.2 - 1.4

-1.2 - 1.4 = -2.6:

-1.3 x = -2.6

Divide both sides of -1.3 x = -2.6 by -1.3:

(-1.3 x)/(-1.3) = (-2.6)/(-1.3)

(-1.3)/(-1.3) = 1:

x = (-2.6)/(-1.3)

(-2.6)/(-1.3) = 2.:

Answer: x = 2.

4 0

3 years ago