Answer:
a. Scatterplot is attached.
b. Positive Correlation
c. Correlation coefficient=0.9219
Step-by-step explanation:
a.
The following procedure will be used to obtain the scatter plot
- Open an Google Sheets file online or excel sheet on your computer.
- In column B and C, enter the Income and Vacation data as provided above.
- Select the data > click on insert CHART.
- Chose Scatter Chart option
A scatter plot visualizing your data should be displayed as attached.
b.
- On your computer, open a spreadsheet in Google Sheets.
- Double-click on your scatter plot.
- At the right, click on Customize tab and then Series.
- Scroll down and check the Trend line box
-From the trend line, your notice that your variables have a positive correlation.
-As the income increases, so does vacation expenditure.
c. The correlation coefficient can be calculated as follows.
- Click on any empty cell in the sheet and enter the formula
- "=CORREL((y-axis range),(x-axis range))"
- ENTER
-From our Google Sheets calculation our variables have a positive correlation and the correlation coefficient is 0.9219
-The correlation coefficient,r can also be calculated manually:
-let x be income, and y be vacation and divide all the values by 100 to make the smaller and easier to manipulate:
![r=\frac{n(\sum xy)-(\sum x)(\sum y)}{\sqrt{[n\sum x^2-(\sum x)^2][n\sum y^2-(\sum y)^2}}\\\\\\\sum xy=153914\\\sum x=4485\\\sum y=246\\\sum x^2=2878447\\(\sum x)^2=4485^2=20115225\\(\sum y)^2=246^2=60516\\\sum y^2=8392\\n=8\\\\\#substitute \ and \ solve \ for \ r\\\\=\frac{8\times153914-4485\times 246}{\sqrt{[8\times 2878447-4485^2][8\times 8392-246^2]}}\\\\=0.92186\\\\\approx 0.9219](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-%28%5Csum%20x%29%5E2%5D%5Bn%5Csum%20y%5E2-%28%5Csum%20y%29%5E2%7D%7D%5C%5C%5C%5C%5C%5C%5Csum%20xy%3D153914%5C%5C%5Csum%20x%3D4485%5C%5C%5Csum%20y%3D246%5C%5C%5Csum%20x%5E2%3D2878447%5C%5C%28%5Csum%20x%29%5E2%3D4485%5E2%3D20115225%5C%5C%28%5Csum%20y%29%5E2%3D246%5E2%3D60516%5C%5C%5Csum%20y%5E2%3D8392%5C%5Cn%3D8%5C%5C%5C%5C%5C%23substitute%20%5C%20and%20%5C%20solve%20%5C%20for%20%5C%20r%5C%5C%5C%5C%3D%5Cfrac%7B8%5Ctimes153914-4485%5Ctimes%20246%7D%7B%5Csqrt%7B%5B8%5Ctimes%202878447-4485%5E2%5D%5B8%5Ctimes%208392-246%5E2%5D%7D%7D%5C%5C%5C%5C%3D0.92186%5C%5C%5C%5C%5Capprox%200.9219)
Answer:
The equation for the amount of salary after x number of years is given by:

where
a is the initial amount
x represents the number of years and
r represents the growth rate( in decimal)
As per the statement:
You begin your first day as a police officer earning $30,000/yr
⇒ a= 30,000
It is also given that you obtain a full 5% increase each year,
⇒
then;
....[1]
we have to find the salary in three years.
⇒
Substitute this value in [1] we have
Simplify:

therefore, your salary be in three years will be $34,4728.75
Answer:
After 5 minutes, the BAC was increasing at the rate of 0.0137 mg/mL a minute.
Step-by-step explanation:
The average blood alcohol concentration (bac) is modeled by the following function.

In which t is measured in minuted.
How rapidly was the BAC increasing after 5 minutes?
This is c'(t) when t = 5.
Using the derivative of the product.
Derivative of the product:


In which problem:


So


After 5 minutes, the BAC was increasing at the rate of 0.0137 mg/mL a minute.