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Finding the Fourth Proportional to 686.18, 1,029.36 and 253.28

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Solution

The fourth proportional to 686.18, 1,029.36 and 253.28 is: 379.95

Step by Step Solution

  1. Step 1: Write the proportion equation
    686.18 : 1,029.36 = 253.28 : x
  2. Step 2: Convert to fraction form
    686.18/1,029.36 = 253.28/x
  3. Step 3: Cross multiply
    686.18x = 1,029.36 × 253.28
  4. Step 4: Simplify right side
    686.18x = 260,716.30
  5. Step 5: Solve for x
    x = 260,716.30/686.18
  6. Step 6: Final answer
    x = 379.95

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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.