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Finding the Fourth Proportional to 628.34, 867.21 and 392.43

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Solution

The fourth proportional to 628.34, 867.21 and 392.43 is: 541.62

Step by Step Solution

  1. Step 1: Write the proportion equation
    628.34 : 867.21 = 392.43 : x
  2. Step 2: Convert to fraction form
    628.34/867.21 = 392.43/x
  3. Step 3: Cross multiply
    628.34x = 867.21 × 392.43
  4. Step 4: Simplify right side
    628.34x = 340,319.22
  5. Step 5: Solve for x
    x = 340,319.22/628.34
  6. Step 6: Final answer
    x = 541.62

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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.