(a) Composite wage rate =((prevailing wages + prevailing benefits for carpenter) + (prevailing wages + prevailing benefits for electrician) + (prevailing wages + prevailing benefits for plumber)) / 3.

(b) Cost of labor index = 100 + (0.55 × (National Producer Price Index (NPPI) for the construction industry − 100)) + (0.45× (statewide Current Employment Statistics Index (CESI) for the construction industry − 100)), where both the NPPI and the CESI are first adjusted to reflect percentage change from a common base year.

(c) Composite weighted average hourly wage for construction industry employees = ((average hourly wage for SIC 15 employees statewide) (total number of SIC 15 employees statewide) +(average hourly wage for SIC 17 employees statewide) (total number of SIC 17 employees statewide)) / (total number of SIC 15 and SIC 17 employees statewide).