Marcia dissolved 1 kg of salt in 3 litres of water. Bobby dissolves 2 pounds of salt in 7 pints of water 2.11 pints = 1 litre 7 pints = 7/2.11 = 3.32 litre 1 pound =0.45 kg 2 pound = o.45*2 kg = 0.9 kg So we find that Bobby is dissolving 0.9kg of salt in 3.32 litre of water Marcia is dissolving 1 kg of salt in 3 litres of water. So it can be said that Marcia made a more concentrated salt solution.
The mean of the answer is 20.5 because you add all of the number together and divide by 6 because there's 6 numbers. I'm sorry, but I don't know how to do the standard deviation... Hope this helped!
