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!