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Finding the Fourth Proportional to 422.52, 629.76 and 389.64

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Solution

The fourth proportional to 422.52, 629.76 and 389.64 is: 580.75

Step by Step Solution

  1. Step 1: Write the proportion equation
    422.52 : 629.76 = 389.64 : x
  2. Step 2: Convert to fraction form
    422.52/629.76 = 389.64/x
  3. Step 3: Cross multiply
    422.52x = 629.76 × 389.64
  4. Step 4: Simplify right side
    422.52x = 245,379.69
  5. Step 5: Solve for x
    x = 245,379.69/422.52
  6. Step 6: Final answer
    x = 580.75

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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.