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Finding the Fourth Proportional to 422.21, 628.59 and 420.18

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Solution

The fourth proportional to 422.21, 628.59 and 420.18 is: 625.56

Step by Step Solution

  1. Step 1: Write the proportion equation
    422.21 : 628.59 = 420.18 : x
  2. Step 2: Convert to fraction form
    422.21/628.59 = 420.18/x
  3. Step 3: Cross multiply
    422.21x = 628.59 × 420.18
  4. Step 4: Simplify right side
    422.21x = 264,118.85
  5. Step 5: Solve for x
    x = 264,118.85/422.21
  6. Step 6: Final answer
    x = 625.56

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Why These Related Problems?

These problems maintain the same ratio (1.49) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.