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Finding the Fourth Proportional to 528.78, 791.31 and 485.56

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Solution

The fourth proportional to 528.78, 791.31 and 485.56 is: 726.63

Step by Step Solution

  1. Step 1: Write the proportion equation
    528.78 : 791.31 = 485.56 : x
  2. Step 2: Convert to fraction form
    528.78/791.31 = 485.56/x
  3. Step 3: Cross multiply
    528.78x = 791.31 × 485.56
  4. Step 4: Simplify right side
    528.78x = 384,228.48
  5. Step 5: Solve for x
    x = 384,228.48/528.78
  6. Step 6: Final answer
    x = 726.63

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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.