[Solved] Provide the equation for the acid dissociate constant, K<sub>a</sub>,for the following equilibrium. \(\mathrm{HA}+\mathrm{H}_{2} \mathrm{O} \rightleftharpoons \mathrm{A}^{-}+\mathrm{H}_{3} \mathrm{O}^{+}\) Activity Variance: The difference between the actual cost incurred for an activity and the standard cost set for that same activity. Total Expenses: The sum of all costs and expenditures that a business incurs during a given period, including operating expenses, cost of goods sold, and other charges. Variable Cost: Costs that vary directly with the level of production or sales volume, such as materials and labor. Flexible Budget: A budget that adjusts or flexes with changes in volume or activity, allowing better comparisons and analysis of performance.