over a period of 200 years, the total output of an economy has grown from $30 billion to $3,000 billion. Its labour force has grown from 1.5 million to 17 million, while its capital stock has increased from $7 billion to $800 billion. Calculate the contributions to economic growth of total factor productivity when the elasticity of output with respect to labour is 0.75 and the elasticity of output with respect to capital is 0.25