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Finding the Fourth Proportional to 666.62, 919.51 and 638.47

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Solution

The fourth proportional to 666.62, 919.51 and 638.47 is: 880.68

Step by Step Solution

  1. Step 1: Write the proportion equation
    666.62 : 919.51 = 638.47 : x
  2. Step 2: Convert to fraction form
    666.62/919.51 = 638.47/x
  3. Step 3: Cross multiply
    666.62x = 919.51 × 638.47
  4. Step 4: Simplify right side
    666.62x = 587,079.55
  5. Step 5: Solve for x
    x = 587,079.55/666.62
  6. Step 6: Final answer
    x = 880.68

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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.