5. An empty graduated cylinder has a mass of 50 grams. The cylinder has a mass of 120
grams when 30 milliliters of water is poured in. If a rock is added to the graduated
cylinder, then water level rises to 75 milliliters and the mass is now 250 grams. Determine
the density of the rock.

1. according to the internal revenue service, the mean tax refund for the year 2007 was $2,708. assume the standard deviation is $650 and that the amounts refunded follow a normal probability distribution. a. what percent of the refunds are more than $3,000? b. what percent of the refunds are more than $3,000 but less than $4,000? c. what percent of the refunds are less than $2,000?