Find the density function for the difference between the production volume and the volume sold. ** assume that both production and sales are normally distributed **

Gasoline (thousands of barrels daily) Sales Production 187.3 764.5 164.1 222.5 276.8 776.7 804.5 758.5 245.6 800.6 793.0 207.2 212.7 228.7 751.0 766.0 215.5 729.1 171.7 177.7 739.0 737.0 Year Month 2018 January February March April May June July August September October November December 2019 January February March April May June July August September October November December 2020 January February 173.0 153.1 217.1 745.0 706.8 730.2 208.4 722.9 199.9 217.3 745.1 741.0 723.8 215.1 223.8 225.7 734.7 721.4 688.1 203.1 701.0 177.6 200.4 694.2 733.0 202.4 198.7 163.9 666.7 676.0 Gasoline (thousands of barrels daily) Sales Production 187.3 764.5 164.1 222.5 276.8 776.7 804.5 758.5 245.6 800.6 793.0 207.2 212.7 228.7 751.0 766.0 215.5 729.1 171.7 177.7 739.0 737.0 Year Month 2018 January February March April May June July August September October November December 2019 January February March April May June July August September October November December 2020 January February 173.0 153.1 217.1 745.0 706.8 730.2 208.4 722.9 199.9 217.3 745.1 741.0 723.8 215.1 223.8 225.7 734.7 721.4 688.1 203.1 701.0 177.6 200.4 694.2 733.0 202.4 198.7 163.9 666.7 676.0