Suppose that heights of newborns are bell shaped with a mean of 6.8 pounds and a standard deviation of 1.3 pounds. What percentage of weights are:

a) Below 6.8 lbs.?

b) Above 8.3 lbs.?

You seem to have confused heights with weights. Perhaps a typo error.

a) 50%, since 6.8 is the mean

b) 8.3 is 1.5 pounds above the mean. That is 1.15 standard deviations. 12.4% are above 8.3 pounds