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Finding the Fourth Proportional to 680.72, 939.74 and 418.88

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Solution

The fourth proportional to 680.72, 939.74 and 418.88 is: 578.27

Step by Step Solution

  1. Step 1: Write the proportion equation
    680.72 : 939.74 = 418.88 : x
  2. Step 2: Convert to fraction form
    680.72/939.74 = 418.88/x
  3. Step 3: Cross multiply
    680.72x = 939.74 × 418.88
  4. Step 4: Simplify right side
    680.72x = 393,638.55
  5. Step 5: Solve for x
    x = 393,638.55/680.72
  6. Step 6: Final answer
    x = 578.27

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Why These Related Problems?

These problems maintain the same ratio (1.38) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.