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Finding the Fourth Proportional to 2,100, 2,898.72 and 1,272

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Solution

The fourth proportional to 2,100, 2,898.72 and 1,272 is: 1,755.80

Step by Step Solution

  1. Step 1: Write the proportion equation
    2,100 : 2,898.72 = 1,272 : x
  2. Step 2: Convert to fraction form
    2,100/2,898.72 = 1,272/x
  3. Step 3: Cross multiply
    2,100x = 2,898.72 × 1,272
  4. Step 4: Simplify right side
    2,100x = 3,687,171.84
  5. Step 5: Solve for x
    x = 3,687,171.84/2,100
  6. Step 6: Final answer
    x = 1,755.80

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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.