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Finding the Fourth Proportional to 686.22, 1,035.56 and 665.70

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Solution

The fourth proportional to 686.22, 1,035.56 and 665.70 is: 1,004.59

Step by Step Solution

  1. Step 1: Write the proportion equation
    686.22 : 1,035.56 = 665.70 : x
  2. Step 2: Convert to fraction form
    686.22/1,035.56 = 665.70/x
  3. Step 3: Cross multiply
    686.22x = 1,035.56 × 665.70
  4. Step 4: Simplify right side
    686.22x = 689,368.96
  5. Step 5: Solve for x
    x = 689,368.96/686.22
  6. Step 6: Final answer
    x = 1,004.59

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Why These Related Problems?

These problems maintain the same ratio (1.51) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.