Students holding a Car Wash Day washed 12 cars in the first hour, 15 cars in the next hour, and 10 cars in each of the next 4 hours. They earned $60 in the hour, and $50 in the third hour. How much money did they earn in all?

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