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Finding the Fourth Proportional to 686.08, 1,028.64 and 412.28

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Solution

The fourth proportional to 686.08, 1,028.64 and 412.28 is: 618.13

Step by Step Solution

  1. Step 1: Write the proportion equation
    686.08 : 1,028.64 = 412.28 : x
  2. Step 2: Convert to fraction form
    686.08/1,028.64 = 412.28/x
  3. Step 3: Cross multiply
    686.08x = 1,028.64 × 412.28
  4. Step 4: Simplify right side
    686.08x = 424,087.70
  5. Step 5: Solve for x
    x = 424,087.70/686.08
  6. Step 6: Final answer
    x = 618.13

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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.