Margin of Error of a Confidence Interval

Hey all,
So I have a question that asks to find the margin of error from a confidence interval for a population mean, the confidence interval has a length of 162.6.
The only way I can find to obtain the margin of error is with zalpha/2 x standard deviation/ square root of n and I don't have any of that information. Can someone explain to me how to figure out this problem? I feel like it's really simple but I can't for the life of me figure this out! My textbook and professors notes aren't really clearing things up.
Thank you!
my confidence interval is 162.6, so would i add and subtract 2.4 to it and that would be my margin of error? (i got the 2.4 from textbook, there was a little blurb on using 2.4 to creat margins of error) that's kind of the only thing i can think of since the length of my confidence interval is the only information given, unless i'm just totally missing the point.


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Let's say you had a mean of 30 and you calculated your margin of error to be 5. What would your confidence interval be? How long is that interval? How does that length relate to your margin of error?