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Finding the Fourth Proportional to 519.45, 775.49 and 428.32

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Solution

The fourth proportional to 519.45, 775.49 and 428.32 is: 639.44

Step by Step Solution

  1. Step 1: Write the proportion equation
    519.45 : 775.49 = 428.32 : x
  2. Step 2: Convert to fraction form
    519.45/775.49 = 428.32/x
  3. Step 3: Cross multiply
    519.45x = 775.49 × 428.32
  4. Step 4: Simplify right side
    519.45x = 332,157.88
  5. Step 5: Solve for x
    x = 332,157.88/519.45
  6. Step 6: Final answer
    x = 639.44

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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.