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Finding the Fourth Proportional to 723.38, 1,085.28 and 261.15

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Solution

The fourth proportional to 723.38, 1,085.28 and 261.15 is: 391.80

Step by Step Solution

  1. Step 1: Write the proportion equation
    723.38 : 1,085.28 = 261.15 : x
  2. Step 2: Convert to fraction form
    723.38/1,085.28 = 261.15/x
  3. Step 3: Cross multiply
    723.38x = 1,085.28 × 261.15
  4. Step 4: Simplify right side
    723.38x = 283,420.87
  5. Step 5: Solve for x
    x = 283,420.87/723.38
  6. Step 6: Final answer
    x = 391.80

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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.