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Finding the Fourth Proportional to 1,128.71, 1,691.65 and 512.71

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Solution

The fourth proportional to 1,128.71, 1,691.65 and 512.71 is: 768.42

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,128.71 : 1,691.65 = 512.71 : x
  2. Step 2: Convert to fraction form
    1,128.71/1,691.65 = 512.71/x
  3. Step 3: Cross multiply
    1,128.71x = 1,691.65 × 512.71
  4. Step 4: Simplify right side
    1,128.71x = 867,325.87
  5. Step 5: Solve for x
    x = 867,325.87/1,128.71
  6. Step 6: Final answer
    x = 768.42

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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.