For the standard normal curve, find the z-score that corresponds to the 90th percentile.

The 90th percentile refers to the value above 90 percent of the data. This is illustrated in the figure.

Using a z-table(also attached) or a technology, we can solve that  z=1.28.

Well in order to lose a pound you would have to burn 1,500 calories. the more calories you burn the more weight you lose. in order to lose 2 pounds you would have to run 4 hours and 28 minutes.