Amusic school has budgeted to purchase 3 musical instruments. they plan to purchase a piano costing $4,000, a guitar costing $600, and a drum set costing $750. the mean cost for a piano is $5,000 with a standard deviation of $2,000. the mean cost for a guitar is $550 with a standard deviation of $250. the mean cost for drums is $950 with a standard deviation of $100. (enter your answers to two decimal places.) how many standard deviations above or below the average piano cost is the piano