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Finding the Fourth Proportional to 666.61, 919.90 and 371.87

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Solution

The fourth proportional to 666.61, 919.90 and 371.87 is: 513.17

Step by Step Solution

  1. Step 1: Write the proportion equation
    666.61 : 919.90 = 371.87 : x
  2. Step 2: Convert to fraction form
    666.61/919.90 = 371.87/x
  3. Step 3: Cross multiply
    666.61x = 919.90 × 371.87
  4. Step 4: Simplify right side
    666.61x = 342,081.35
  5. Step 5: Solve for x
    x = 342,081.35/666.61
  6. Step 6: Final answer
    x = 513.17

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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.