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Finding the Fourth Proportional to 21,138, 29,170.38 and 12,185.43

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Solution

The fourth proportional to 21,138, 29,170.38 and 12,185.43 is: 16,815.86

Step by Step Solution

  1. Step 1: Write the proportion equation
    21,138 : 29,170.38 = 12,185.43 : x
  2. Step 2: Convert to fraction form
    21,138/29,170.38 = 12,185.43/x
  3. Step 3: Cross multiply
    21,138x = 29,170.38 × 12,185.43
  4. Step 4: Simplify right side
    21,138x = 355,453,623.56
  5. Step 5: Solve for x
    x = 355,453,623.56/21,138
  6. Step 6: Final answer
    x = 16,815.86

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1.5x scale

Why These Related Problems?

These problems maintain the same ratio (1.38) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.