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Finding the Fourth Proportional to 515.72, 772.68 and 429.61

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Solution

The fourth proportional to 515.72, 772.68 and 429.61 is: 643.67

Step by Step Solution

  1. Step 1: Write the proportion equation
    515.72 : 772.68 = 429.61 : x
  2. Step 2: Convert to fraction form
    515.72/772.68 = 429.61/x
  3. Step 3: Cross multiply
    515.72x = 772.68 × 429.61
  4. Step 4: Simplify right side
    515.72x = 331,951.05
  5. Step 5: Solve for x
    x = 331,951.05/515.72
  6. Step 6: Final answer
    x = 643.67

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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.