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Finding the Fourth Proportional to 668.64, 1,000.67 and 421.73

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Solution

The fourth proportional to 668.64, 1,000.67 and 421.73 is: 631.15

Step by Step Solution

  1. Step 1: Write the proportion equation
    668.64 : 1,000.67 = 421.73 : x
  2. Step 2: Convert to fraction form
    668.64/1,000.67 = 421.73/x
  3. Step 3: Cross multiply
    668.64x = 1,000.67 × 421.73
  4. Step 4: Simplify right side
    668.64x = 422,012.61
  5. Step 5: Solve for x
    x = 422,012.61/668.64
  6. Step 6: Final answer
    x = 631.15

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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.