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Finding the Fourth Proportional to 698.28, 1,039.83 and 690.61

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Solution

The fourth proportional to 698.28, 1,039.83 and 690.61 is: 1,028.41

Step by Step Solution

  1. Step 1: Write the proportion equation
    698.28 : 1,039.83 = 690.61 : x
  2. Step 2: Convert to fraction form
    698.28/1,039.83 = 690.61/x
  3. Step 3: Cross multiply
    698.28x = 1,039.83 × 690.61
  4. Step 4: Simplify right side
    698.28x = 718,115.27
  5. Step 5: Solve for x
    x = 718,115.27/698.28
  6. Step 6: Final answer
    x = 1,028.41

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Why These Related Problems?

These problems maintain the same ratio (1.49) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.