the sample mean is the midpoint of the interval - compute (8.79-5.09)/2=1.85, and then add the lower bound,

so 5.09+1.85=6.94 is the sample mean.

The margin of error is how far the upper bound is the the mean, so 8.79-6.94=1.85 (which is also how far the sample mean is from the lower bound).

OMG! YOU NEED TO THROUGH THE PAPER AWAY AS SOON AS POSSIBLE LITE I ON FIRE AND BURN IT