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Finding the Fourth Proportional to 686.80, 948 and 490.36

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Solution

The fourth proportional to 686.80, 948 and 490.36 is: 676.85

Step by Step Solution

  1. Step 1: Write the proportion equation
    686.80 : 948 = 490.36 : x
  2. Step 2: Convert to fraction form
    686.80/948 = 490.36/x
  3. Step 3: Cross multiply
    686.80x = 948 × 490.36
  4. Step 4: Simplify right side
    686.80x = 464,861.28
  5. Step 5: Solve for x
    x = 464,861.28/686.80
  6. Step 6: Final answer
    x = 676.85

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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.