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Finding the Fourth Proportional to 686.13, 946.95 and 420.60

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Solution

The fourth proportional to 686.13, 946.95 and 420.60 is: 580.48

Step by Step Solution

  1. Step 1: Write the proportion equation
    686.13 : 946.95 = 420.60 : x
  2. Step 2: Convert to fraction form
    686.13/946.95 = 420.60/x
  3. Step 3: Cross multiply
    686.13x = 946.95 × 420.60
  4. Step 4: Simplify right side
    686.13x = 398,287.17
  5. Step 5: Solve for x
    x = 398,287.17/686.13
  6. Step 6: Final answer
    x = 580.48

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Why These Related Problems?

These problems maintain the same ratio (1.38) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.