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Finding the Fourth Proportional to 666.64, 919.78 and 404.65

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Solution

The fourth proportional to 666.64, 919.78 and 404.65 is: 558.31

Step by Step Solution

  1. Step 1: Write the proportion equation
    666.64 : 919.78 = 404.65 : x
  2. Step 2: Convert to fraction form
    666.64/919.78 = 404.65/x
  3. Step 3: Cross multiply
    666.64x = 919.78 × 404.65
  4. Step 4: Simplify right side
    666.64x = 372,188.98
  5. Step 5: Solve for x
    x = 372,188.98/666.64
  6. Step 6: Final answer
    x = 558.31

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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.