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Finding the Fourth Proportional to 668.25, 1,003.25 and 421.54

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Solution

The fourth proportional to 668.25, 1,003.25 and 421.54 is: 632.86

Step by Step Solution

  1. Step 1: Write the proportion equation
    668.25 : 1,003.25 = 421.54 : x
  2. Step 2: Convert to fraction form
    668.25/1,003.25 = 421.54/x
  3. Step 3: Cross multiply
    668.25x = 1,003.25 × 421.54
  4. Step 4: Simplify right side
    668.25x = 422,908.55
  5. Step 5: Solve for x
    x = 422,908.55/668.25
  6. Step 6: Final answer
    x = 632.86

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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.