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Finding the Fourth Proportional to 521.76, 720.02 and 285.72

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Solution

The fourth proportional to 521.76, 720.02 and 285.72 is: 394.29

Step by Step Solution

  1. Step 1: Write the proportion equation
    521.76 : 720.02 = 285.72 : x
  2. Step 2: Convert to fraction form
    521.76/720.02 = 285.72/x
  3. Step 3: Cross multiply
    521.76x = 720.02 × 285.72
  4. Step 4: Simplify right side
    521.76x = 205,724.11
  5. Step 5: Solve for x
    x = 205,724.11/521.76
  6. Step 6: Final answer
    x = 394.29

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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.