Answer:

Step-by-step explanation:
In 5 liters, there is 4% salt.
Lets find liters of salt.
First, converting 4% to decimal (dividing by 100):
4% = 4/100 = 0.04
0.04 * 5 = 0.2
So, there is 0.2 liters of salt.
Now, x liters of water is added to total, so total is now:
5 + x
The concentration of salt will be amount of salt divided by amount of salt water solution.
Amount of salt = 0.2 (as seen above)
Amount of new salt water solution = x + 5
So,
Concentration of salt in new solution is 
2nd choice is right.
Answer:
The second one
Step-by-step explanation:
Answer:
For the first city, the 95% confidence interval would be:
28,900 +/- 2300 x 3 = 28,900 +/-6900$
For the second city, the 95% confidence interval would be:
30,300 +/- 2100 x 3 = 30,300 +/- 6300$