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Finding the Fourth Proportional to 686.22, 1,029.66 and 678.66

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Solution

The fourth proportional to 686.22, 1,029.66 and 678.66 is: 1,018.32

Step by Step Solution

  1. Step 1: Write the proportion equation
    686.22 : 1,029.66 = 678.66 : x
  2. Step 2: Convert to fraction form
    686.22/1,029.66 = 678.66/x
  3. Step 3: Cross multiply
    686.22x = 1,029.66 × 678.66
  4. Step 4: Simplify right side
    686.22x = 698,789.06
  5. Step 5: Solve for x
    x = 698,789.06/686.22
  6. Step 6: Final answer
    x = 1,018.32

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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.