Labor Code section 510, subdivision (a) provides: "Eight hours of labor constitutes a day's work. Any work in excess of eight hours in one workday and any work in excess of 40 hours in any one workweek and the first eight hours worked on the seventh day of work in any one workweek shall be compensated at the rate of no less than one and one-half times the regular rate of pay for an employee. Any work in excess of 12 hours in one day shall be compensated at the rate of no less than twice the regular rate of pay for an employee. In addition, any work in excess of eight hours on any seventh day of a workweek shall be compensated at the rate of no less than twice the regular rate of pay of an employee. . . ." Labor Code sections 226.7 and 512 mandate that non-exempt employees receive a 30-minute meal break for every five hours worked. An employer who fails to provide such a break shall pay the employee one additional hour of pay. (Lab. Code, 226.7, subd. (b).) The California Industrial Welfare Commission (IWC) is the "state agency empowered to formulate regulations (known as wage orders) governing minimum wages, maximum hours, and overtime pay in the State of California." (Ramirez v. Yosemite Water Co., Inc. (1999) 20 Cal.4th 785, 795 (Ramirez).) Pursuant to Labor Code section 515, subdivision (a), the IWC may establish exemptions from the payment of overtime for executive, administrative, and professional employees "provided that the employee is primarily engaged in the duties that meet the test of the exemption, customarily and regularly exercises discretion and independent judgment in performing those duties, and earns a monthly salary equivalent to no less than two times the state minimum wage for full-time employment. . . ." "Exemptions from statutory mandatory overtime provisions are narrowly construed." (Ramirez, supra, 20 Cal.4th at p. 794.) Moreover, "the assertion of an exemption from the overtime laws is considered to be an affirmative defense, and therefore the employer bears the burden of proving the employee's exemption." (Id. at pp. 794-795.) The question of whether an exemption exists is a mixed question of law and fact. (Ramirez, supra, 20 Cal.App.4th at p. 794.) To the extent we review the construction or interpretation of the statute, we review the lower court's ruling de novo. To the extent that the Good Nite Inns are challenging the lower court's findings, we use the substantial evidence standard of review. Under this standard, "'"the power of an appellate court begins and ends with a determination as to whether there is any substantial evidence, contradicted or uncontradicted," to support the findings below.We must therefore view the evidence in the light most favorable to the prevailing party, giving it the benefit of every reasonable inference and resolving all conflicts in its favor in accordance with the standard of review so long adhered to by this court. ''The substantial evidence standard applies to both express and implied findings of fact made by the superior court in its statement of decision rendered after a nonjury trial. '" (Escamilla v. Department of Corrections & Rehabilitation (2006) 141 Cal.App.4th 498, 514 (Escamilla).) "'Substantial evidence' is evidence of ponderable legal significance, evidence that is reasonable, credible and of solid value.'Substantial evidence . . . is not synonymous with "any" evidence.' . . .The focus is on the quality, rather than the quantity, of the evidence." (Roddenberry v. Roddenberry (1996) 44 Cal.App.4th 634, 651.) "'It is not our task to weigh conflicts and disputes in the evidence; that is the province of the trier of fact. . . . We do not evaluate the credibility of the witnesses or otherwise reweigh the evidence.Rather, 'we defer to the trier of fact on issues of credibility. '" (Escamilla, supra, 141 Cal.App.4th at pp. 514-515.) Indeed, "testimony of a witness offered in support of a judgment may not be rejected on appeal unless it is physically impossible or inherently improbable and such inherent improbability plainly appears." (Beck Development Co. v. Southern Pacific Transportation Co. (1996) 44 Cal.App.4th 1160, 1204.) When the record as a whole shows a reasonable trier of fact could have found in favor of the respondent, we must affirm. (Kuhn v. Department of General Services (1994) 22 Cal.App.4th 1627, 1633.)