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Finding the Fourth Proportional to 355.72, 490.23 and 257.31

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Solution

The fourth proportional to 355.72, 490.23 and 257.31 is: 354.61

Step by Step Solution

  1. Step 1: Write the proportion equation
    355.72 : 490.23 = 257.31 : x
  2. Step 2: Convert to fraction form
    355.72/490.23 = 257.31/x
  3. Step 3: Cross multiply
    355.72x = 490.23 × 257.31
  4. Step 4: Simplify right side
    355.72x = 126,141.08
  5. Step 5: Solve for x
    x = 126,141.08/355.72
  6. Step 6: Final answer
    x = 354.61

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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.