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2 years ago

Find AB using the segment addition postulate.

Mathematics

1 answer:

Elena-2011 [213]2 years ago

7 0

Answer : AB = 12

Explanation:

2x + 6 + 5x - 3 = 24
7x + 3 = 24
x = 3

AB = 2x + 6 = 2(3) + 6 = 12

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GARY DREW A RECTANGLE WITH A PERIMETER OF 20 INCHES. WHAT COULD BE THE LENGTH,WIDTH,AND AREA FOR THE RECTANGLE THAT GARY DREW?

Ilia_Sergeevich [38]

Assume L=1.5W, where W=width, L= Length of the triangle.

Therefore,

Perimeter (P) = 2(W+L) = 2(W+1.5W) = 2(2.5W) = 5W=20 => W=20/5 = 4 in

Then, L=1.5W = 1.5*4 = 6 in

Area, A= L*W = 6*4 = 24 in^2

8 0

3 years ago

Modern medical practice tells us not to encourage babies to become too fat. Is there a positive correlation between the weight x

Anna11 [10]

Answer:

a) Figure attached

b) $y=1.31 x +98.57$

c) The correlation coefficient would be r =0.47719

d) $y=1.31 x +98.57=1.31*21 + 98.57 =126.08$

Step-by-step explanation:

(a) Draw a scatter diagram for the data.

See the figure attached

(b) Find x, y, b, and the equation of the least-squares line. (Round your answers to three decimal places.) x =__ y =__ b =__ y =__ + __x

$m=\frac{S_{xy}}{S_{xx}}$

Where:

$S_{xy}=\sum_{i=1}^n x_i y_i -\frac{(\sum_{i=1}^n x_i)(\sum_{i=1}^n y_i)}{n}$

$S_{xx}=\sum_{i=1}^n x^2_i -\frac{(\sum_{i=1}^n x_i)^2}{n}$

With these we can find the sums:

$S_{xx}=\sum_{i=1}^n x^2_i -\frac{(\sum_{i=1}^n x_i)^2}{n}=6576-\frac{300^2}{14}=147.429$

$S_{xy}=\sum_{i=1}^n x_i y_i -\frac{(\sum_{i=1}^n x_i)(\sum_{i=1}^n y_i){n}}=38186-\frac{300*1773}{14}=193.143$

And the slope would be:

$m=\frac{193.143}{147.429}=1.31$

Nowe we can find the means for x and y like this:

$\bar x= \frac{\sum x_i}{n}=\frac{300}{14}=21.429$

$\bar y= \frac{\sum y_i}{n}=\frac{1773}{14}=126.643$

And we can find the intercept using this:

$b=\bar y -m \bar x=126.643-(1.31*21.429)=98.571$

So the line would be given by:

$y=1.31 x +98.57$

(c) Find the sample correlation coefficient r and the coefficient of determination r?2. (Round your answers to three decimal places.)

n=14 $\sum x = 300, \sum y = 1773, \sum xy=38186, \sum x^2 =6576, \sum y^2 =225649$

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

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

$r=\frac{14(38186)-(300)(1773)}{\sqrt{[14(6576) -(300)^2][14(225649) -(1773)^2]}}=0.9534$

So then the correlation coefficient would be r =0.47719

What percentage of variation in y is explained by the least-squares model? (Round your answer to one decimal place.)

The % of variation is given by the determination coefficient given by $r^2$ and on this case $0.47719^2 =0.2277$ , so then the % of variation explaines is 22.8%.

(d) If a female baby weighs 21 pounds at 1 year, what do you predict she will weigh at 30 years of age? (Round your answer to two decimal places.) ___ lb

So we can replace in the linear model like this:

$y=1.31 x +98.57=1.31*21 + 98.57 =126.08$

7 0

3 years ago

Help me on this math question

Gnom [1K]

Answer:

Arithmetic

Step-by-step explanation:

7 0

2 years ago

Read 2 more answers

Any help is appreciated, check the picture above for the question.

Aleksandr-060686 [28]

Answer:

y + 5 > -2 i.e. option 4.

Step-by-step explanation:

An inequality is shown in the number line by an arrow and we have to identify the inequality from the options given.

It is clear from the given figure that the y variable is plotted and its value is greater than - 7 but not including - 7.

Therefore, option 4 which gives the inequality y + 5 > -2 will be the correct answer.

As it gives y > - 2 - 5 i.e. y > - 7 (Answer)

8 0

3 years ago

Divide by 2, and then subtract the sum of 9 and 4

erma4kov [3.2K]

Answer:

Step-by-step explanation:

You can set this up by reversing it.

(9+4)- (x/2)

(13)-(x/2)

(13)-(2x)

=11x

3 0

3 years ago