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Finding the Fourth Proportional to 721.31, 1,081.35 and 356.20

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Solution

The fourth proportional to 721.31, 1,081.35 and 356.20 is: 534.00

Step by Step Solution

  1. Step 1: Write the proportion equation
    721.31 : 1,081.35 = 356.20 : x
  2. Step 2: Convert to fraction form
    721.31/1,081.35 = 356.20/x
  3. Step 3: Cross multiply
    721.31x = 1,081.35 × 356.20
  4. Step 4: Simplify right side
    721.31x = 385,174.17
  5. Step 5: Solve for x
    x = 385,174.17/721.31
  6. Step 6: Final answer
    x = 534.00

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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.