Use the Circumference Formula of a Circle: C=2(pi)(r). The radius is the length from the center to a point on the circle. The circumference is essentially the perimeter of the circle, so the “edge” around the circle is the circumference.
Answer:
Constant of proportionality: 
Equation: 
Step-by-step explanation:
By definition, Direct proportion equations have the following form:

Where "k" is the Constant of proportionality.
In this case, let be "c" the the amount of caffeine consumed (in mg) from a glass of Diet Pepsi and "d" the number of ounces that was drank.
So, the equation that represents this relationship will have this form:

Then, the first step is to find the Constant of proportionality "k".
Knowing that:

We can substitute values into the equation:

Now, solving for "k", we get:

Therefore, we can write the following equation that represents that proportional relationship:

Answer:
B = 3.75t
Step-by-step explanation:
Given;
initial charge of Arianna's phone = 45%
the charge remaining in Arianna battery = 15%
If after 4hours of leaving her house, the battery had 15% remaining battery life, then the battery is discharging at the rate of ( 15% / 4hours) 3.75% per hour.
Thus, the charge remaining in Arianna's battery after she left her house is given by;
B = 3.75t
where;
t is time in hours
B is the percentage of charge remaining
Answer:
The value of the test statistic is 
Step-by-step explanation:
The null hypothesis is:

The alternate hypotesis is:

Our test statistic is:

In which X is the sample mean,
is the value tested at the null hypothesis,
is the standard deviation and n is the size of the sample.
In this problem, we have that:

Then



The value of the test statistic is 
x^2+6x-5=0
x^2=2x
2x+6x-5=0
2x+6x=8x
8x-5=0
+5 +5
(if you don’t know what I’m doing here is that I’m removing the negative 5 by putting a positive 5 since both of them make 0. Also the “x” always stay alone and the unit stays as the unit)
(I putted the positive under the 0 because what u do to the unit you need to do the same thing with the other.)
8x/8=5/8
(If ur lost here it means dividing.)
The answer
X=0.625
(btw I’m not really sure if this is right so um don’t really trust me in this lol)