Which of the following could cause a favorable labor rate variance? Any of the choices could cause a favorable labor rate variance. None of the choices could cause a favorable labor rate variance Fewer factory workers were needed than expected to complete the same amount of production work in the period. Worker's compensation insurance rates increased from the prior period There was an unexpected reduction in state and federal payroll taxes in the middle of the period. Less time was needed than expected for a company's assembly line workers to complete each unit of product in a given period