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Finding the Fourth Proportional to 686.24, 947.02 and 391.50

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Solution

The fourth proportional to 686.24, 947.02 and 391.50 is: 540.28

Step by Step Solution

  1. Step 1: Write the proportion equation
    686.24 : 947.02 = 391.50 : x
  2. Step 2: Convert to fraction form
    686.24/947.02 = 391.50/x
  3. Step 3: Cross multiply
    686.24x = 947.02 × 391.50
  4. Step 4: Simplify right side
    686.24x = 370,758.33
  5. Step 5: Solve for x
    x = 370,758.33/686.24
  6. Step 6: Final answer
    x = 540.28

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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.