Answer:
a) 
b) r =-0.932
The % of variation is given by the determination coefficient given by 
and on this case 
, so then the % of variation explained by the linear model is 86.87%.
Step-by-step explanation:
Assuming the following dataset:
Monthly Sales (Y) Interest Rate (X)
22 9.2
20 7.6
10 10.4
45 5.3
Part a
And we want a linear model on this way y=mx+b, where m represent the slope and b the intercept. In order to find the slope we have this formula:
Where:
With these we can find the sums:
And the slope would be:
Nowe we can find the means for x and y like this:
And we can find the intercept using this:
So the line would be given by:
Part b
For this case we need to calculate the correlation coefficient given by:
![r=\frac{n(\sum xy)-(\sum x)(\sum y)}{\sqrt{[n\sum x^2 -(\sum x)^2][n\sum y^2 -(\sum y)^2]}}](https://tex.z-dn.net/?f=r%3D%5Cfrac%7Bn%28%5Csum%20xy%29-%28%5Csum%20x%29%28%5Csum%20y%29%7D%7B%5Csqrt%7B%5Bn%5Csum%20x%5E2%20-%28%5Csum%20x%29%5E2%5D%5Bn%5Csum%20y%5E2%20-%28%5Csum%20y%29%5E2%5D%7D%7D)
![r=\frac{4(696.9)-(32.5)(97)}{\sqrt{[4(278.65) -(32.5)^2][4(3009) -(97)^2]}}=-0.937](https://tex.z-dn.net/?f=r%3D%5Cfrac%7B4%28696.9%29-%2832.5%29%2897%29%7D%7B%5Csqrt%7B%5B4%28278.65%29%20-%2832.5%29%5E2%5D%5B4%283009%29%20-%2897%29%5E2%5D%7D%7D%3D-0.937)
So then the correlation coefficient would be r =-0.932
The % of variation is given by the determination coefficient given by and on this case , so then the % of variation explained by the linear model is 86.87%.
<span>The mean of tree heights at Yard Works is 7 feet The mean of tree heights at Yard Works is 8 feet The mean of tree heights at The Grow Station is 9 feet The mean of tree heights at these are the correct answers
</span>
Answer:
This idea of reflection correlating with a mirror image is similar in math.
This complete guide to reflecting over the x axis and reflecting over the y axis will provide a step-by-step tutorial on how to perform these translations.
First, let’s start with a reflection geometry definition
Math Definition: Reflection Over the X Axis
A reflection of a point, a line, or a figure in the X axis involved reflecting the image over the x axis to create a mirror image. In this case, the x axis would be called the axis of reflection.
Math Definition: Reflection Over the Y Axis
A reflection of a point, a line, or a figure in the Y axis involved reflecting the image over the Y axis to create a mirror image. In this case, theY axis would be called the axis of reflection.
What is the rule for a reflection across the X axis?
The rule for reflecting over the X axis is to negate the value of the y-coordinate of each point, but leave the x-value the same.
This is an exponential decay problem.
Using the equation Y = a *(1-rate)^time
where Y is the future value given as 12,000 and a is the starting value given as 13,000.
The rate is also given as 5%.
The equation becomes:
12,000 = 13,000(1-0.05)^x
12,000 = 13,000(0.95)^x
Divide each side by 13000:
12000/13000 = 0.95^x/13000
12/13 = 0.95^x
Use the natural log function:
x = ln(12/13) / ln(0.95)
x = 1.56 years. ( this will equal 12,000
Round to 2 years it will be less than 12000.
To find the answer,we need to first find out their hours spent individually.
Rishi spent:
=2×3/4
=6/4hours
Kyle spent
=6×1/4
=6/4hours
As they both spent 6/4 hours,they spent equal time.
Hope it helps!
