Answer:
The margin of error is of 0.01.
Step-by-step explanation:
We have that to find our
level, that is the subtraction of 1 by the confidence interval divided by 2. So:

Now, we have to find z in the Z-table as such z has a p-value of
.
That is z with a pvalue of
, so Z = 1.037.
The margin of error is of:

In which
is the standard deviation of the population and n is the size of the sample.
Standard deviation was 0.21.
This means that 
Sample of 450:
This means that 
What is the margin of error, assuming a 70% confidence level, to the nearest hundredth?



The margin of error is of 0.01.