Answer:
The sample size to obtain the desired margin of error is 160.
Step-by-step explanation:
The Margin of Error is given as

Rearranging this equation in terms of n gives
![n=\left[z_{crit}\times \dfrac{\sigma}{M}\right]^2](https://tex.z-dn.net/?f=n%3D%5Cleft%5Bz_%7Bcrit%7D%5Ctimes%20%5Cdfrac%7B%5Csigma%7D%7BM%7D%5Cright%5D%5E2)
Now the Margin of Error is reduced by 2 so the new M_2 is given as M/2 so the value of n_2 is calculated as
![n_2=\left[z_{crit}\times \dfrac{\sigma}{M_2}\right]^2\\n_2=\left[z_{crit}\times \dfrac{\sigma}{M/2}\right]^2\\n_2=\left[z_{crit}\times \dfrac{2\sigma}{M}\right]^2\\n_2=2^2\left[z_{crit}\times \dfrac{\sigma}{M}\right]^2\\n_2=4\left[z_{crit}\times \dfrac{\sigma}{M}\right]^2\\n_2=4n](https://tex.z-dn.net/?f=n_2%3D%5Cleft%5Bz_%7Bcrit%7D%5Ctimes%20%5Cdfrac%7B%5Csigma%7D%7BM_2%7D%5Cright%5D%5E2%5C%5Cn_2%3D%5Cleft%5Bz_%7Bcrit%7D%5Ctimes%20%5Cdfrac%7B%5Csigma%7D%7BM%2F2%7D%5Cright%5D%5E2%5C%5Cn_2%3D%5Cleft%5Bz_%7Bcrit%7D%5Ctimes%20%5Cdfrac%7B2%5Csigma%7D%7BM%7D%5Cright%5D%5E2%5C%5Cn_2%3D2%5E2%5Cleft%5Bz_%7Bcrit%7D%5Ctimes%20%5Cdfrac%7B%5Csigma%7D%7BM%7D%5Cright%5D%5E2%5C%5Cn_2%3D4%5Cleft%5Bz_%7Bcrit%7D%5Ctimes%20%5Cdfrac%7B%5Csigma%7D%7BM%7D%5Cright%5D%5E2%5C%5Cn_2%3D4n)
As n is given as 40 so the new sample size is given as

So the sample size to obtain the desired margin of error is 160.
Answer:
C
Step-by-step explanation:
to figure this out, lets understand how decimals work
a decimal number in the tens place before the decimal
↓ here
0.00
that number will be the same number as the numerator or top number of a fraction in tenths
↓ here
0/10
so say it was 4/10 we needed to find, we would look on the number line for 0.40 like in answer choice B (NOT THE CORRECT ANSWER FOR THIS PROBLEM)
hope this helps you out on your work :)
Answer:
LMN has a larger area
Step-by-step explanation:
Given
RST



LMN



Required
Compare both areas
The area of triangle is:

For RST, we have:


Remove absolute signs


For LMN, we have:



Remove absolute signs


<em>By comparing both areas, we can conclude that LMN has a larger area</em>
Answer:
I think it is C
Step-by-step explanation:
Reason being because the question said at least 15 points more so it can't
be 12 equal to 12 points. so you could eliminate the greater than or equal to.
so that leaves c and d. can't see how it is D because if he has 15 points more can't see why his other portion of points could take away 15 so that leaves C.
hope that helps