The rate of change of annual U.S. factory sales (in billions of dollars per year) of consumer electronic goods to dealers from 1990 through 2001 can be modeled as

s(t) = 0.12t²t+ 5.7 billion dollars per year wheretis the number of years since 1990.

(a) Use a limit of sums to estimate the change in factory sales from 1990 through 2001. (Round your answer to one decimal place.)

$(blank) billion

(b) If factory sales were $43.1billion in 1990, what were they in 2001? (Round your answer to one decimal place.)

$(blank) billion

Please fill in the blanks and state answers clearly.