2/3÷4/5 equals what ?

Some types of algae have the potential to cause damage to river ecosystems. Suppose the accompanying data on algae colony densit

kondor19780726 [428]

Answer:

The equation of the regression line is:

$y~=~234.56158 ~-~ 2.95835 \cdot x$

Step-by-step explanation:

The Least Squares Regression Line is the line that makes the vertical distance from the data points to the regression line as small as possible. It’s called a “least squares” because the best line of fit is one that minimizes the variance.

We have the following data:

$\begin{array}{c|ccccccccc}X&50&55&50&79&44&37&70&45&49\\Y&152&48&22&35&43&171&13&185&25\end{array}$

To find the line of best fit for the points:

Step 1: Find $X\cdot X$ and $X\cdot Y$ as it was done in the table

Step 2: Find the sum of every column:

$\sum{X} = 479 ~,~ \sum{Y} = 694 ~,~ \sum{X \cdot Y} = 32784 ~,~ \sum{X^2} = 26897$

Step 3: Use the following equations to find a and b:

$\begin{aligned} a &= \frac{\sum{Y} \cdot \sum{X^2} - \sum{X} \cdot \sum{XY} }{n \cdot \sum{X^2} - \left(\sum{X}\right)^2} = \frac{ 694 \cdot 26897 - 479 \cdot 32784}{ 9 \cdot 26897 - 479^2} \approx 234.56158 \\ \\b &= \frac{ n \cdot \sum{XY} - \sum{X} \cdot \sum{Y}}{n \cdot \sum{X^2} - \left(\sum{X}\right)^2} = \frac{ 9 \cdot 32784 - 479 \cdot 694 }{ 9 \cdot 26897 - \left( 479 \right)^2} \approx -2.95835\end{aligned}$

Step 4: Assemble the equation of a line

$\begin{aligned} y~&=~a ~+~ b \cdot x \\y~=~234.56158 ~-~ 2.95835\cdot x\end{aligned}$

The graph of the regression line is:

5 0

4 years ago

Y - 4 = -2 (x+3) find missing value in the solution

devlian [24]

Answer:

Not solveable

Step-by-step explanation:

because that to solve the two unkown number you must have two equations of it in order to solve it

7 0

4 years ago

Which question(s) could be answered by collecting data that has variability? Click on each statistical question. To change an an

Annette [7]

Answer:

No
No
Yes
No
Yes

A statistical question is one that can be answered in numbers.

4 0

3 years ago

Craig threw a handful of identically shaped buttons into the air then collected 14 bottoms that landed on the carpet. Is this sa

olga55 [171]

Answer:

possible?? but I think that there is a typo, and that there would not be a bias

Step-by-step explanation:

can we assume that there are no typos in the question

he threw BUTTONS in the air, and look at buttons that landed with the BOTTOMS facing up ??? in that case the weight might bias the orientation of the landing... I think that you have a typo and it just says that he collected 14 BUTTONS, in that case given that they are "IDENTICAL" we most likely can assume that there would be no bias (size color, texture are all the same)

8 0

3 years ago

Can y’all please help me answer these questions

mario62 [17]

Step-by-step explanation:

4.

⇒ $V = \pi r^{2}h$