Please help me with this statistics problem

bottles of water are normally distributed with a mean of 20.0 oz and a standard deviation of .31.

Find the volume of water that seperates the top 8% with the botton 92%. In other words the top 8% of bottles are filled more than what?

find the volumes that contain the middle 80%. In other words 80% of bottles in the distribution are filled between what and what?

The president of the water co has decided to ship between 19.85 and 20.35 ounces. How much of the water that is produced will actually be shipped to consumers? Is this a good business decision?

You get a bottle that is filled with 20.89 ounces. WHat is the probability of getting a bottle filled wsith at least this much? Is thata rarity?