Henry and Jessica skipping rocks across the surface of a pond for every nine rocks at Henry throws he got five of them to skip across the pond for every twelve rocks Jessica throws she got seven of them to skip across the pond who gets more rocks to skip across the surface of the pond​

The birth weights of newborn babies in the unites states follow in a normal distrubution with a mean of 3.4 kg and standard deviation of 0.6 kg. reaserches interested in studying how. children gain weights decide to take random samples of 100 newborn babies and calculate the sample mean birth weights for each sample