John Burton runs a blacksmith's workshop. His electricity bills come in every quarter. The current year's information included the following:

i.On January 1, there was an unpaid bill covering the quarter to December 15 of the previous year of $250.

ii.Usage from December 15 to December 31 of the previous year was estimated to be $50.

iii.Bills received during the year were as follows:

Quarter for December 15 to March 15: $350, paid in April

Quarter for March 15 to June 15: $500, paid in June

Quarter for June 15 to Sept. 15: $ 450, paid in October

Quarter for September 15 to December 15: $350, still unpaid at the end of the year.

iv.Estimated usage from December 15 to December 31: $100.

Calculate the electricity expense for the year.