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Finding the Fourth Proportional to 12,128, 18,192 and 3,920

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Solution

The fourth proportional to 12,128, 18,192 and 3,920 is: 5,880

Step by Step Solution

  1. Step 1: Write the proportion equation
    12,128 : 18,192 = 3,920 : x
  2. Step 2: Convert to fraction form
    12,128/18,192 = 3,920/x
  3. Step 3: Cross multiply
    12,128x = 18,192 × 3,920
  4. Step 4: Simplify right side
    12,128x = 71,312,640
  5. Step 5: Solve for x
    x = 71,312,640/12,128
  6. Step 6: Final answer
    x = 5,880

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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.