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Finding the Fourth Proportional to 551.78, 760.07 and 420.56

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Solution

The fourth proportional to 551.78, 760.07 and 420.56 is: 579.31

Step by Step Solution

  1. Step 1: Write the proportion equation
    551.78 : 760.07 = 420.56 : x
  2. Step 2: Convert to fraction form
    551.78/760.07 = 420.56/x
  3. Step 3: Cross multiply
    551.78x = 760.07 × 420.56
  4. Step 4: Simplify right side
    551.78x = 319,649.14
  5. Step 5: Solve for x
    x = 319,649.14/551.78
  6. Step 6: Final answer
    x = 579.31

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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.