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Finding the Fourth Proportional to 611.10, 843.15 and 389.87

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Solution

The fourth proportional to 611.10, 843.15 and 389.87 is: 537.91

Step by Step Solution

  1. Step 1: Write the proportion equation
    611.10 : 843.15 = 389.87 : x
  2. Step 2: Convert to fraction form
    611.10/843.15 = 389.87/x
  3. Step 3: Cross multiply
    611.10x = 843.15 × 389.87
  4. Step 4: Simplify right side
    611.10x = 328,717.11
  5. Step 5: Solve for x
    x = 328,717.11/611.10
  6. Step 6: Final answer
    x = 537.91

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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.