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Finding the Fourth Proportional to 429.70, 645.08 and 427.72

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Solution

The fourth proportional to 429.70, 645.08 and 427.72 is: 642.12

Step by Step Solution

  1. Step 1: Write the proportion equation
    429.70 : 645.08 = 427.72 : x
  2. Step 2: Convert to fraction form
    429.70/645.08 = 427.72/x
  3. Step 3: Cross multiply
    429.70x = 645.08 × 427.72
  4. Step 4: Simplify right side
    429.70x = 275,915.30
  5. Step 5: Solve for x
    x = 275,915.30/429.70
  6. Step 6: Final answer
    x = 642.12

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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.