1. **State the problem:** An investor has stock in two companies: Company A worth 2000 and Company B worth 1050 last year. Company A's stock decreased by 22% and Company B's stock decreased by 10%. We need to find the total percentage decrease in the investor's combined stock value. 2. **Formula and rules:** The percentage decrease for each stock is given. To find the total percentage decrease, first find the new values of each stock after the decrease, then find the total decrease relative to the original total. 3. **Calculate the new value of Company A's stock:** $$\text{New value A} = 2000 \times (1 - 0.22) = 2000 \times 0.78 = 1560$$ 4. **Calculate the new value of Company B's stock:** $$\text{New value B} = 1050 \times (1 - 0.10) = 1050 \times 0.90 = 945$$ 5. **Calculate the original total value:** $$\text{Original total} = 2000 + 1050 = 3050$$ 6. **Calculate the new total value:** $$\text{New total} = 1560 + 945 = 2505$$ 7. **Calculate the total decrease:** $$\text{Decrease} = 3050 - 2505 = 545$$ 8. **Calculate the total percentage decrease:** $$\text{Percentage decrease} = \frac{545}{3050} \times 100 = \frac{\cancel{545}}{\cancel{3050}} \times 100 \approx 17.9\%$$ **Final answer:** The total percentage decrease in the investor's stock account is approximately **17.9%**.