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Finding the Fourth Proportional to 686.41, 947.26 and 387.67

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Solution

The fourth proportional to 686.41, 947.26 and 387.67 is: 534.99

Step by Step Solution

  1. Step 1: Write the proportion equation
    686.41 : 947.26 = 387.67 : x
  2. Step 2: Convert to fraction form
    686.41/947.26 = 387.67/x
  3. Step 3: Cross multiply
    686.41x = 947.26 × 387.67
  4. Step 4: Simplify right side
    686.41x = 367,224.28
  5. Step 5: Solve for x
    x = 367,224.28/686.41
  6. Step 6: Final answer
    x = 534.99

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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.