The output of a process is valued at $100 per unit. The cost of labor is $50 per hour including benefits. The accounting department provided the following information about the process for the past four weeks: Week 1 Week 2 Week 3 Week 4 Units Produced 1 ,1 24 1 ,31 0 1 ,092 981 Labor ($) 1 2,735 1 4,842 1 0,603 9,526 Material ($) 21 ,041 24,523 20,442 1 8,364 Overhead ($) 8,992 1 0,480 8,736 7,848 b. Has labor productivity changed? Use the labor productivity ratio to support your answer and show each weeks ratio.