Answer:

Step-by-step explanation:
Given:
Width of average grain of salt is, 
Width of Rhinovirus is, 
Now, expressing each width in scientific notation form, we get:

Now, in order to get how many times 'W' is wider than 'w', we divide the two widths. This gives,

Therefore, the grain of salt is
wider than Rhinovirus.
5(t)
It will be $5 times however many weeks
<h3>
Answer: Choice C</h3>
Explanation:
As the person spends more time raking, the number of leaves will go down. Therefore, we have a negative correlation. Such correlations occur when one variable goes up while the other goes down (and vice versa).
The reason why it's considered negative correlation is because the regression line has a negative slope.
This is why choice C is the answer. This assumes that no extra leaves fall on the ground, and we assume that we don't have nearby leaves blow into the yard.
In contrast, something like choice A has both variables go up together. As the temperature rises, so does the ice cream sales. The same goes for choice B. We consider these cases to have positive correlation. Choice D doesn't appear to have any correlation at all. The person's height doesn't have any connection to the number of pets they may have.
Answer:
- The system of equations is x + y = 85 and 7/20x+2/5y=31
- To eliminate the x-variable from the equations, you can multiply the equation with the fractions by 20 and multiply the other equation by -7.
- B-She used 60 minutes for calling and 25 minutes for data.
Step-by-step explanation:
It is always a good idea to start by defining variables in such a problem. Here, we can let x represent the number of calling minutes, and y represent the number of data minutes. The the total number of minutes used is ...
x + y = 85
The total of charges is the sum of the products of charge per minute and minutes used:
7/20x + 2/5y = 31.00
We can eliminate the x-variable in these equations by multiplying the first by -7 and the second by 20, then adding the result.
-7(x +y) +20(7/20x +2/5y) = -7(85) +20(31)
-7x -7y +7x +8y = -595 +620 . . . . eliminate parentheses
y = 25 . . . . . . . . simplify
Then the value of x is
x = 85 -y = 85 -25
x = 60