A chemical supply company currently has 50 gallons of mercury. This company sells half- gallon containers. let X be the number of containers ordered by a randomly selected customer, and suppose the probability mass function of X is given by 1 2 4 p(x)? 0.22 0.21 0.26 What is the expected value of X?

What layer of the atmosphere is directly above the troposphere?

The volume of helium in a blimp is 6.28 x 10^9 millimeters. the density of helium in the blimp is .1786 kilogram/meter^3. find the mass of the helium in the blimp.

If we compare and contrast electromagnetic waves with sound waves, all but one statement is true. that is a) sound waves require a medium to travel while electromagnetic waves do not. b) electromagnetic waves can travel through the vacuum of space while sound waves cannot. c) electromagnetic waves must have a medium in which to travel, but sound waves can travel anywhere. eliminate d) sound waves must bounce off of matter in order to travel while electromagnetic waves do not require matter to be present.