The table shows the minimum wage rates for the United States during different years.
Year
1978
1979
1980
1990
1991
1996
1997
2007
2008
2009
Minimum hourly wage ($)
2.65
2.90
3.35
3.80
4.25
4.75
5.15
5.85
6.55
7.25


(a) Write the least squares regression equation that models the data. Let x = time in years since 1900 and let y = minimum hourly wage.
(b) Use the equation to estimate the minimum hourly wage of a U.S. worker in 2025. Show your work.
Answer: