Can somebody please answer my question!

When interest is compounded continuously, the amount of money increases at a rate proportional to the amount s present at time t, that is, ds/dt = rs, where r is the annual rate of interest. (a) find the amount of money accrued at the end of 3 years when $4000 is deposited in a savings account drawing 5 3 4 % annual interest compounded continuously. (round your answer to the nearest cent.) $ (b) in how many years will the initial sum deposited have doubled? (round your answer to the nearest year.) years (c) use a calculator to compare the amount obtained in part (a) with the amount s = 4000 1 + 1 4 (0.0575) 3(4) that is accrued when interest is compounded quarterly. (round your answer to the nearest cent.) s = $

What impact might an economic downturn have on a borrower’s fixed-rate mortgage? a. it might cause a borrower’s payments to go up. b. it might cause a borrower’s payments to go down. c. it has no impact because a fixed-rate mortgage cannot change. d. it has no impact because the economy does not affect interest rates.

By 2020, automobile market analysts expect that the demand for electric autos will increase as buyers become more familiar with the technology. however, the costs of producing electric autos may increase because of higher costs for inputs (e.g., rare earth elements), or they may decrease as the manufacturers learn better assembly methods (i.e., learning by doing). what is the expected impact of these changes on the equilibrium price and quantity for electric autos?