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Finding the Fourth Proportional to 686.61, 1,029.92 and 199.71

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Solution

The fourth proportional to 686.61, 1,029.92 and 199.71 is: 299.57

Step by Step Solution

  1. Step 1: Write the proportion equation
    686.61 : 1,029.92 = 199.71 : x
  2. Step 2: Convert to fraction form
    686.61/1,029.92 = 199.71/x
  3. Step 3: Cross multiply
    686.61x = 1,029.92 × 199.71
  4. Step 4: Simplify right side
    686.61x = 205,684.32
  5. Step 5: Solve for x
    x = 205,684.32/686.61
  6. Step 6: Final answer
    x = 299.57

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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.