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Finding the Fourth Proportional to 723.54, 1,085.13 and 312.78

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Solution

The fourth proportional to 723.54, 1,085.13 and 312.78 is: 469.09

Step by Step Solution

  1. Step 1: Write the proportion equation
    723.54 : 1,085.13 = 312.78 : x
  2. Step 2: Convert to fraction form
    723.54/1,085.13 = 312.78/x
  3. Step 3: Cross multiply
    723.54x = 1,085.13 × 312.78
  4. Step 4: Simplify right side
    723.54x = 339,406.96
  5. Step 5: Solve for x
    x = 339,406.96/723.54
  6. Step 6: Final answer
    x = 469.09

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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.