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Finding the Fourth Proportional to 689.20, 1,029.61 and 685.96

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Solution

The fourth proportional to 689.20, 1,029.61 and 685.96 is: 1,024.77

Step by Step Solution

  1. Step 1: Write the proportion equation
    689.20 : 1,029.61 = 685.96 : x
  2. Step 2: Convert to fraction form
    689.20/1,029.61 = 685.96/x
  3. Step 3: Cross multiply
    689.20x = 1,029.61 × 685.96
  4. Step 4: Simplify right side
    689.20x = 706,271.28
  5. Step 5: Solve for x
    x = 706,271.28/689.20
  6. Step 6: Final answer
    x = 1,024.77

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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.