In class recently we have learned about confidence intervals and sampling distributions. I am not sure specifically what topic this particular question falls under/ what formula is involved. Any suggestions on how to get started would be appreciated. Thanks.

Question:

Among 30 children (aged five to six years) living in a particular neighborhood, the standard deviation of diastolic blood pressure is 7.9mm Hg and the mean diastolic blood pressure is 56.2mm Hg. A national study indicates that the mean diastolic blood pressure is 64.2 mm Hg for children aged five to six years. Is there evidence that the mean diastolic blood pressure for children in the neighborhood differs from the national mean diastolic blood pressure for children aged five to six years? Any thoughts on how to approach this question? Thanks.