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Finding the Fourth Proportional to 686.89, 947.91 and 372.15

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Solution

The fourth proportional to 686.89, 947.91 and 372.15 is: 513.56

Step by Step Solution

  1. Step 1: Write the proportion equation
    686.89 : 947.91 = 372.15 : x
  2. Step 2: Convert to fraction form
    686.89/947.91 = 372.15/x
  3. Step 3: Cross multiply
    686.89x = 947.91 × 372.15
  4. Step 4: Simplify right side
    686.89x = 352,762.59
  5. Step 5: Solve for x
    x = 352,762.59/686.89
  6. Step 6: Final answer
    x = 513.56

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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.