The answer is A. for this, you have to set up a system of equations. the first one will be the area equation. since you know area=length x width, your equation will be LxW=50. the next equation is L=2W, since the length is two times the width. then, plug in 2W for the L in the other equation and you get 2W^2=50. divide by 2 and get W^2=25. square root both sides and you get W=5. plug back into the other equation to find L=10. Then, add the sides of the rectangle for the perimeter. 10+5+10+5=30.
Answer:
And we can find the limits in order to consider values as significantly low and high like this:
Step-by-step explanation:
Previous concepts
A confidence interval is "a range of values that’s likely to include a population value with a certain degree of confidence. It is often expressed a % whereby a population means lies between an upper and lower interval".
The margin of error is the range of values below and above the sample statistic in a confidence interval.
Normal distribution, is a "probability distribution that is symmetric about the mean, showing that data near the mean are more frequent in occurrence than data far from the mean".
Solution to the problem
For this case we can consider a value to be significantly low if we have that the z score is lower or equal to - 2 and we can consider a value to be significantly high if its z score is higher tor equal to 2.
For this case we have the mean and the deviation given:
And we can find the limits in order to consider values as significantly low and high like this:
Simplifying-
(6d^2)(-7d)=
= -(42d^2)(d)
=-42d^3
The situation can be modeled by a geometric sequence with an initial term of 284. The student population will be 104% of the prior year, so the common ratio is 1.04.
Let \displaystyle PP be the student population and \displaystyle nn be the number of years after 2013. Using the explicit formula for a geometric sequence we get
{P}_{n} =284\cdot {1.04}^{n}P
n
=284⋅1.04
n
We can find the number of years since 2013 by subtracting.
\displaystyle 2020 - 2013=72020−2013=7
We are looking for the population after 7 years. We can substitute 7 for \displaystyle nn to estimate the population in 2020.
\displaystyle {P}_{7}=284\cdot {1.04}^{7}\approx 374P
7
=284⋅1.04
7
≈374
The student population will be about 374 in 2020.