Under usual conditions, a distillation unit in a refinery can process a mean of 135,000 barrels per day of crude petroleum, with a standard deviation of 6,000 barrels per day. You may assume the normal distribution.

1. Find the probability that the number of barrels processed on a given day will be between 125,000 and 140,000.

2. Suppose that yesterday the refinery was working much slower than usual and processed less oil that it normally does in 80% of all days. How many barrels of oil were processed yesterday? You may round it to the nearest barrel (up or down, doesn't matter).

Please use excel to solve for the above. Include formulas and explanation