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Finding the Fourth Proportional to 280.52, 420.31 and 172.09

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Solution

The fourth proportional to 280.52, 420.31 and 172.09 is: 257.85

Step by Step Solution

  1. Step 1: Write the proportion equation
    280.52 : 420.31 = 172.09 : x
  2. Step 2: Convert to fraction form
    280.52/420.31 = 172.09/x
  3. Step 3: Cross multiply
    280.52x = 420.31 × 172.09
  4. Step 4: Simplify right side
    280.52x = 72,331.15
  5. Step 5: Solve for x
    x = 72,331.15/280.52
  6. Step 6: Final answer
    x = 257.85

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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.