A music school has budgeted to purchase three musical instruments. They plan to purchase a piano costing $3,500$3,500, a guitar costing $400$400, and a drum set costing $625$625. The mean cost for a piano is $4,000$4,000 with a standard deviation of $2,500$2,500. The mean cost for a guitar is $500$500 with a standard deviation of $200$200. The mean cost for drums is $700$700 with a standard deviation of $100$100.

Which cost is the lowest, when compared to other instruments of the same type? Which cost is the highest, when compared to other instruments of the same type? Justify your answer.

The drumset has the lowest cost when compared to other instruments of the same type since it has the lowest z-score of ______

The piano has the highest cost when compared to other instruments of the same type since it has the highest z-score of ______