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Finding the Fourth Proportional to 422.10, 631.86 and 257.12

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Solution

The fourth proportional to 422.10, 631.86 and 257.12 is: 384.89

Step by Step Solution

  1. Step 1: Write the proportion equation
    422.10 : 631.86 = 257.12 : x
  2. Step 2: Convert to fraction form
    422.10/631.86 = 257.12/x
  3. Step 3: Cross multiply
    422.10x = 631.86 × 257.12
  4. Step 4: Simplify right side
    422.10x = 162,463.84
  5. Step 5: Solve for x
    x = 162,463.84/422.10
  6. Step 6: Final answer
    x = 384.89

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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.