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Finding the Fourth Proportional to 681.80, 939.80 and 557.26

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Solution

The fourth proportional to 681.80, 939.80 and 557.26 is: 768.13

Step by Step Solution

  1. Step 1: Write the proportion equation
    681.80 : 939.80 = 557.26 : x
  2. Step 2: Convert to fraction form
    681.80/939.80 = 557.26/x
  3. Step 3: Cross multiply
    681.80x = 939.80 × 557.26
  4. Step 4: Simplify right side
    681.80x = 523,712.95
  5. Step 5: Solve for x
    x = 523,712.95/681.80
  6. Step 6: Final answer
    x = 768.13

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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.