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Finding the Fourth Proportional to 666.88, 999.68 and 422.72

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Solution

The fourth proportional to 666.88, 999.68 and 422.72 is: 633.67

Step by Step Solution

  1. Step 1: Write the proportion equation
    666.88 : 999.68 = 422.72 : x
  2. Step 2: Convert to fraction form
    666.88/999.68 = 422.72/x
  3. Step 3: Cross multiply
    666.88x = 999.68 × 422.72
  4. Step 4: Simplify right side
    666.88x = 422,584.73
  5. Step 5: Solve for x
    x = 422,584.73/666.88
  6. Step 6: Final answer
    x = 633.67

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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.