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Finding the Fourth Proportional to 519.72, 778.22 and 427.40

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Solution

The fourth proportional to 519.72, 778.22 and 427.40 is: 639.98

Step by Step Solution

  1. Step 1: Write the proportion equation
    519.72 : 778.22 = 427.40 : x
  2. Step 2: Convert to fraction form
    519.72/778.22 = 427.40/x
  3. Step 3: Cross multiply
    519.72x = 778.22 × 427.40
  4. Step 4: Simplify right side
    519.72x = 332,611.23
  5. Step 5: Solve for x
    x = 332,611.23/519.72
  6. Step 6: Final answer
    x = 639.98

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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.