What unit would you use to measure the mass of an object

In an experiment you are to flip a two sided coin 100 times and record 55 heads up and 45 tails up determine the theoretical and experimental probability of getting a heads up in the experiment.

Find the x-intercepts of the parabola withvertex (1,1) and y-intercept (0,-3).write your answer in this form: (x1,if necessary, round to the nearest hundredth.

The radius of a sphere is 3 inches. which represents the volume of the sphere?