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Finding the Fourth Proportional to 523.21, 721.80 and 355.11

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Solution

The fourth proportional to 523.21, 721.80 and 355.11 is: 489.90

Step by Step Solution

  1. Step 1: Write the proportion equation
    523.21 : 721.80 = 355.11 : x
  2. Step 2: Convert to fraction form
    523.21/721.80 = 355.11/x
  3. Step 3: Cross multiply
    523.21x = 721.80 × 355.11
  4. Step 4: Simplify right side
    523.21x = 256,318.40
  5. Step 5: Solve for x
    x = 256,318.40/523.21
  6. Step 6: Final answer
    x = 489.90

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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.