Answer:
6x+2y=-78
Step-by-step explanation:
8x-3y=-70
-2x+5y=-8
6x+2y=-78
The US: 300m World: 9b Most accurate: B
300m•20=6b population
B is the most accurate
Step 1 , switch sides - 29-3b<10
step 2 , subtract 29 from both sides - -3b< -19
step 3 , multiply both sides by -1 - 3b > 19
step 4 (answer) - divide by 3 = 19/3
Answer:



Step-by-step explanation:
Given

Solving (a): Point estimate of difference of mean
This is calculated as: 


Solving (b): 90% confidence interval
We have:


Confidence level is: 



Calculate 


The z score is:

The endpoints of the confidence level is:






Split


Hence, the 90% confidence interval is:

Solving (c): 95% confidence interval
We have:


Confidence level is: 



Calculate 


The z score is:

The endpoints of the confidence level is:






Split


Hence, the 95% confidence interval is:
