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Finding the Fourth Proportional to 686.90, 1,029.45 and 275.70

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Solution

The fourth proportional to 686.90, 1,029.45 and 275.70 is: 413.19

Step by Step Solution

  1. Step 1: Write the proportion equation
    686.90 : 1,029.45 = 275.70 : x
  2. Step 2: Convert to fraction form
    686.90/1,029.45 = 275.70/x
  3. Step 3: Cross multiply
    686.90x = 1,029.45 × 275.70
  4. Step 4: Simplify right side
    686.90x = 283,819.37
  5. Step 5: Solve for x
    x = 283,819.37/686.90
  6. Step 6: Final answer
    x = 413.19

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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.