Disregard anything that is already answered I was guessing. I really need help.

Suppose you are doing a study on the wealth of the population in your town. You take a random survey of 100 people. Which would

Angelina_Jolie [31]

Answer:

D) The total number of people in the population.

Step-by-step explanation:

The answer is D) The total number of people in the population. because it is a quantitative data measurement. All other options, Age, Gender and Education are qaualitative measures, which are aligned with the Objective of the study, Wealth - A qualitative measure too!

4 0

3 years ago

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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

3 years ago

Please help due in 5 minutes !

SpyIntel [72]

The first option is correct

4 0

3 years ago

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A triangle has side lengths measuring 2x + 2 ft, x + 3 ft, and n ft.

brilliants [131]

Answer:

The correct option is A. x – 1 < n < 3x + 5

Step-by-step explanation:

In a triangle sum of any two sides is always greater than the third side.

Now, the sides of the triangle are given to be :

2x + 2, x + 3 , n

Now, first take 2x + 2 and x + 3 as two sides and the side of length n as third side.

By using the property that sum of two sides is always greater than the third side in a triangle.

⇒ 2x + 2 + x + 3 > n

⇒ 3x + 5 > n ......(1)

Now, take n and x + 3 as two sides and the side of length 2x + 2 as the third side of triangle.

So, by the property, we have :

n + x + 3 > 2x + 2

⇒ n > x - 1 ...........(2)

From both the equations (1) and (2) , We get :

x – 1 < n < 3x + 5

Therefore, The correct option is A. x – 1 < n < 3x + 5

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3 years ago

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Please select the best answer from the choices provided A B C D

SSSSS [86.1K]

ANSWER

The correct answer is D.

$\sum_{n=1} ^{6} (n - 3) = ( - 2) + ( - 1) + (0) + (1) + (2) + (3) = 3$

EXPLANATION

The given expression is

$\sum_{n=1} ^{6} (n - 3)$

The symbol means summation.

So we need to substitute

$n=1,n=2,n=3,n=4,n=5, \:and\:n=6$

into the formula and add all to get,

$\sum_{n=1} ^{6} (n - 3) = (1 - 3) + (2 - 3) + (3- 3) + (4 - 3) + (5 - 3) + (6 - 3)$

We simplify to obtain,

$\sum_{n=1} ^{6} (n - 3) = ( - 2) + ( - 1) + (0) + (1) + (2) + (3) = 3$

The correct answer is D

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3 years ago

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