Answer:

Step-by-step explanation:
-The margin of error is calculated using the formula:

-We substitute the values, n=900 and ME=30 in the formula to solve for standard deviation:

Hence, the population standard deviation is 547.1125
Answer:
70,000-50,000=20,000
Step-by-step explanation:
Answer:
x = 5
Step-by-step explanation:
Hope this helps! :D