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Finding the Fourth Proportional to 689.87, 952 and 391.11

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Solution

The fourth proportional to 689.87, 952 and 391.11 is: 539.72

Step by Step Solution

  1. Step 1: Write the proportion equation
    689.87 : 952 = 391.11 : x
  2. Step 2: Convert to fraction form
    689.87/952 = 391.11/x
  3. Step 3: Cross multiply
    689.87x = 952 × 391.11
  4. Step 4: Simplify right side
    689.87x = 372,336.72
  5. Step 5: Solve for x
    x = 372,336.72/689.87
  6. Step 6: Final answer
    x = 539.72

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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.