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Finding the Fourth Proportional to 13,638, 20,457 and 5,430

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Solution

The fourth proportional to 13,638, 20,457 and 5,430 is: 8,145

Step by Step Solution

  1. Step 1: Write the proportion equation
    13,638 : 20,457 = 5,430 : x
  2. Step 2: Convert to fraction form
    13,638/20,457 = 5,430/x
  3. Step 3: Cross multiply
    13,638x = 20,457 × 5,430
  4. Step 4: Simplify right side
    13,638x = 111,081,510
  5. Step 5: Solve for x
    x = 111,081,510/13,638
  6. Step 6: Final answer
    x = 8,145

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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.