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Finding the Fourth Proportional to 666.72, 999.93 and 388.89

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Solution

The fourth proportional to 666.72, 999.93 and 388.89 is: 583.24

Step by Step Solution

  1. Step 1: Write the proportion equation
    666.72 : 999.93 = 388.89 : x
  2. Step 2: Convert to fraction form
    666.72/999.93 = 388.89/x
  3. Step 3: Cross multiply
    666.72x = 999.93 × 388.89
  4. Step 4: Simplify right side
    666.72x = 388,857.78
  5. Step 5: Solve for x
    x = 388,857.78/666.72
  6. Step 6: Final answer
    x = 583.24

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Why These Related Problems?

These problems maintain the same ratio (1.50) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.