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Finding the Fourth Proportional to 666.61, 919.94 and 386.85

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Solution

The fourth proportional to 666.61, 919.94 and 386.85 is: 533.86

Step by Step Solution

  1. Step 1: Write the proportion equation
    666.61 : 919.94 = 386.85 : x
  2. Step 2: Convert to fraction form
    666.61/919.94 = 386.85/x
  3. Step 3: Cross multiply
    666.61x = 919.94 × 386.85
  4. Step 4: Simplify right side
    666.61x = 355,878.79
  5. Step 5: Solve for x
    x = 355,878.79/666.61
  6. Step 6: Final answer
    x = 533.86

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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.