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Finding the Fourth Proportional to 422.40, 628.89 and 422.40

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Solution

The fourth proportional to 422.40, 628.89 and 422.40 is: 628.89

Step by Step Solution

  1. Step 1: Write the proportion equation
    422.40 : 628.89 = 422.40 : x
  2. Step 2: Convert to fraction form
    422.40/628.89 = 422.40/x
  3. Step 3: Cross multiply
    422.40x = 628.89 × 422.40
  4. Step 4: Simplify right side
    422.40x = 265,643.14
  5. Step 5: Solve for x
    x = 265,643.14/422.40
  6. Step 6: Final answer
    x = 628.89

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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.