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Finding the Fourth Proportional to 1,381.89, 2,073.15 and 408

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Solution

The fourth proportional to 1,381.89, 2,073.15 and 408 is: 612.09

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,381.89 : 2,073.15 = 408 : x
  2. Step 2: Convert to fraction form
    1,381.89/2,073.15 = 408/x
  3. Step 3: Cross multiply
    1,381.89x = 2,073.15 × 408
  4. Step 4: Simplify right side
    1,381.89x = 845,845.20
  5. Step 5: Solve for x
    x = 845,845.20/1,381.89
  6. Step 6: Final answer
    x = 612.09

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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.