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2 years ago

PLEASE HELP

Mathematics

1 answer:

vfiekz [6]2 years ago

4 0

Answer:

i think you should look up a yt video to see how to do it lol

Step-by-step explanation:

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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

2 years ago

The ages in years of eight boys are 14,

SashulF [63]

Answer:

B) 13

Step-by-step explanation:

Average age means to calculate mean:

Mean = (Sum of all numbers)/(Number of numbers)

Mean = (14 + 14.5 + 12 + 11.5 + 15 + 13 + 10.5 + 13.5)/8

Mean = (104)/8

Mean = 13

5 0

2 years ago

How would I solve this equation for mass (m)?

zaharov [31]

Simple...

you have: $F= \frac{G m^{2} }{ d^{2} }$

You want to find m-->>>

1.)Isolate m

$d^{2} *F= \frac{G m^{2} }{ d^{2} } * d^{2}$

Leaving you with...

F* $d^{2}$ = $G m^{2}$

Keep isolating m-->>>

$F* d^{2} =G m^{2}$

$\frac{F* d^{2} }{G} = \frac{G m^{2} }{G}$

Square root to solve what just m is-->>>

$\sqrt{ \frac{F* d^{2} }{G} } = \sqrt{ m^{2} }$

= $\sqrt{ \frac{F* d^{2} }{G} } =m$

That is how you solve for m...

Thus, your answer.

7 0

2 years ago

5) What is the distance between the points (3,-5) and (5,6)?

Afina-wow [57]

B 11.2 Have a good day :)

7 0

2 years ago

Partial quotients of 3 divided by 225

Bond [772]

The answer is 75 you could do long division and that will get you the answer.

6 0

2 years ago