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Finding the Fourth Proportional to 686.71, 1,030.58 and 427.09

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Solution

The fourth proportional to 686.71, 1,030.58 and 427.09 is: 640.95

Step by Step Solution

  1. Step 1: Write the proportion equation
    686.71 : 1,030.58 = 427.09 : x
  2. Step 2: Convert to fraction form
    686.71/1,030.58 = 427.09/x
  3. Step 3: Cross multiply
    686.71x = 1,030.58 × 427.09
  4. Step 4: Simplify right side
    686.71x = 440,151.71
  5. Step 5: Solve for x
    x = 440,151.71/686.71
  6. Step 6: Final answer
    x = 640.95

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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.