confidence interval

I'm having so much trouble with this problem if someone could help I'd be so greatful.

Suppose a confidence interval is 19.48 < µ < 21.36. Find the sample mean x¯ (sorry the bar is supposed to be over the x its supposed to be x bar but i cant write that) and the margin of error E.

Use the definition of a symmetric confidence interval for a population mean: it's the sample mean plus or minus the margin of error.