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Finding the Fourth Proportional to 472.76, 707.78 and 427.20

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Solution

The fourth proportional to 472.76, 707.78 and 427.20 is: 639.57

Step by Step Solution

  1. Step 1: Write the proportion equation
    472.76 : 707.78 = 427.20 : x
  2. Step 2: Convert to fraction form
    472.76/707.78 = 427.20/x
  3. Step 3: Cross multiply
    472.76x = 707.78 × 427.20
  4. Step 4: Simplify right side
    472.76x = 302,363.62
  5. Step 5: Solve for x
    x = 302,363.62/472.76
  6. Step 6: Final answer
    x = 639.57

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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.