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Finding the Fourth Proportional to 686.98, 947.80 and 392.04

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Solution

The fourth proportional to 686.98, 947.80 and 392.04 is: 540.88

Step by Step Solution

  1. Step 1: Write the proportion equation
    686.98 : 947.80 = 392.04 : x
  2. Step 2: Convert to fraction form
    686.98/947.80 = 392.04/x
  3. Step 3: Cross multiply
    686.98x = 947.80 × 392.04
  4. Step 4: Simplify right side
    686.98x = 371,575.51
  5. Step 5: Solve for x
    x = 371,575.51/686.98
  6. Step 6: Final answer
    x = 540.88

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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.