<span>1 hour and 1/3rd of an hour
</span>
so A is right
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:2:8
Step-by-step explanation:
divide everything by 7