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Finding the Fourth Proportional to 686.97, 947.64 and 476.78

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Solution

The fourth proportional to 686.97, 947.64 and 476.78 is: 657.69

Step by Step Solution

  1. Step 1: Write the proportion equation
    686.97 : 947.64 = 476.78 : x
  2. Step 2: Convert to fraction form
    686.97/947.64 = 476.78/x
  3. Step 3: Cross multiply
    686.97x = 947.64 × 476.78
  4. Step 4: Simplify right side
    686.97x = 451,811.06
  5. Step 5: Solve for x
    x = 451,811.06/686.97
  6. Step 6: Final answer
    x = 657.69

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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.