A 1982 study indicated that 40% of young adults (18-25 years old) in the U.S.

A 1982 study indicated that 40% of young adults (18-25 years old) in the U.S. smoked cigarettes. In a later survey of 1500 young adults, 536 were found to be smokers. Do the data indicate that the smoking rate for young adults in the U.S. has decreased significantly? (alpha = 0.01)
a) Dose the data indicate the smoking rate for young adults in the US has changed significantly?
b) Use a confidence interval with appropriate level of confidence to conduct the test in a).