All categories

3 years ago

What point located in quadrant IV has an x-value that is 3 units from the origin and a y-value that is 3 units from the origin?

Mathematics

1 answer:

Bess [88]3 years ago

8 0

Answer: X=27y+3r jkjkljlkjlkjljljkljkjkljlkjlkjlkjlkjlkjlkjkljlkjlkj

You might be interested in

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

Solve (x +9)2 = 25.

alexandr1967 [171]

Answer:

$x = - 4 \: or \: x = - 14$

Step-by-step explanation:

We have been given the equation

$(x + 9) {}^{2} = 25$

and we are asked to apply the square root property of equality to our given a equation and isolate the variable

First, take the square root of both sides of our equation

$\sqrt{(x + 9) {}^{2} } = \sqrt{25}$

$x + 9 = \: 15$

$x + 9 = 5 \: or \: x + 9 = - 5$

$x + 9 - 9 = 5 - 9 \: or \: x + 9 - 9 = - 5 - 9$

$x = - 4 \: or \: x = - 14$

THEREFORE, THERE ARE TWO SOLUTIONS FOR OUR GIVEN EQUATION

$x + 9 = 5 \: then \: x = - 4. \\ x + 9 = - 5 \: then \: x = - 14$

PLEASE MAKR ME BRAINLIEST IF YOU ARE HAPPY WITH THE ANSWER

8 0

3 years ago

Please help fast will give brainliest

antoniya [11.8K]

Answer:

THE ANSWER IS C

Step-by-step explanation:

8 0

3 years ago

Read 2 more answers

Please help and show work if you can

laila [671]

Answer:

25. a = 60

26. a = 17

Step-by-step explanation:

In these two problems we are going to use a property of parallelograms that says: opposite angles have equal measure

so we have

25.

$6a+10=130\\\\6a=130-10\\\\6a=120\\\\a=60$

and for 26 we have

$4a-4=2a+30\\\\4a=2a+30+4\\\\4a=2a+34\\\\4a-2a=34\\\\2a=34\\\\a=17$

6 0

3 years ago

The difference of the quotient m and 9 and the quotient of n and 30

Zanzabum

Answer: (30m-9n)/270

First we start with m/9-n/30.

We multiply the denominators to get 270.

Then we multiply the numerators by the original denominators to get (30m-9n).

To check, we can use m=2, and n=4

2/9-4/30=4/45

(30*2-9*4)/270=24/270=4/45

5 0

3 years ago