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Finding the Fourth Proportional to 521.91, 720.09 and 312.09

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Solution

The fourth proportional to 521.91, 720.09 and 312.09 is: 430.60

Step by Step Solution

  1. Step 1: Write the proportion equation
    521.91 : 720.09 = 312.09 : x
  2. Step 2: Convert to fraction form
    521.91/720.09 = 312.09/x
  3. Step 3: Cross multiply
    521.91x = 720.09 × 312.09
  4. Step 4: Simplify right side
    521.91x = 224,732.89
  5. Step 5: Solve for x
    x = 224,732.89/521.91
  6. Step 6: Final answer
    x = 430.60

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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.