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Finding the Fourth Proportional to 660.87, 912 and 381.09

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Solution

The fourth proportional to 660.87, 912 and 381.09 is: 525.90

Step by Step Solution

  1. Step 1: Write the proportion equation
    660.87 : 912 = 381.09 : x
  2. Step 2: Convert to fraction form
    660.87/912 = 381.09/x
  3. Step 3: Cross multiply
    660.87x = 912 × 381.09
  4. Step 4: Simplify right side
    660.87x = 347,554.08
  5. Step 5: Solve for x
    x = 347,554.08/660.87
  6. Step 6: Final answer
    x = 525.90

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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.