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%.
Answer:
She will be charged $180 once lets the account go past 6 months before making a payment.
Step-by-step explanation:
This is a simple interest problem.
The simple interest formula is given by:
In which E is the amount of interest earned, P is the principal(the initial amount of money), I is the interest rate(yearly, as a decimal) and t is the time.
After t years, the total amount of money is:
In this question:
If she pays within 6 months, she is not charged any interest.
However, if after 6 months she has not paid the balance, she is charged 20% interest for this period.
Barbara financed a new bedroom set at the furniture store for $1,800.
This means that 
20 percent interest
This means that 
How much interest will she be charged once she lets the account go past 6 months?
6 months is half a year, so this is E when 
She will be charged $180 once lets the account go past 6 months before making a payment.
Answer:
use calculator
Step-by-step explanation:
Answer:
the approximate range of change is 150 for 3
the approximate range of change is 1600 for 4
between 1970 and 1975
please give me brainlest
Answer:
I have attached a picture of the completed graph.
The equation is k = r + 7
Kyle will be 59 when Ryan is 52.
Explanation:
Kyle's age is always seven years higher than Ryan's age.
Therefore, k (Kyle's age) = r (Ryan's age) + 7 (Number of years different)
