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Finding the Fourth Proportional to 689.70, 1,035.22 and 430.20

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Solution

The fourth proportional to 689.70, 1,035.22 and 430.20 is: 645.72

Step by Step Solution

  1. Step 1: Write the proportion equation
    689.70 : 1,035.22 = 430.20 : x
  2. Step 2: Convert to fraction form
    689.70/1,035.22 = 430.20/x
  3. Step 3: Cross multiply
    689.70x = 1,035.22 × 430.20
  4. Step 4: Simplify right side
    689.70x = 445,351.64
  5. Step 5: Solve for x
    x = 445,351.64/689.70
  6. Step 6: Final answer
    x = 645.72

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Why These Related Problems?

These problems maintain the same ratio (1.50) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.