1. The current population of the United States is 328.2 million with 2.2% of the population is engaged in R&D at an efficiency rate of 1/500 per million persons per year. (a) If R&D is the only source of total-factor productivity growth what is the growth rate of labor efficiency in the United States? (b) If the growth rate of total factor productivity is 0.75% per year, what is the value of a in the Cobb-Douglas production function