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Finding the Fourth Proportional to 412.90, 619.41 and 138.91

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Solution

The fourth proportional to 412.90, 619.41 and 138.91 is: 208.39

Step by Step Solution

  1. Step 1: Write the proportion equation
    412.90 : 619.41 = 138.91 : x
  2. Step 2: Convert to fraction form
    412.90/619.41 = 138.91/x
  3. Step 3: Cross multiply
    412.90x = 619.41 × 138.91
  4. Step 4: Simplify right side
    412.90x = 86,042.24
  5. Step 5: Solve for x
    x = 86,042.24/412.90
  6. Step 6: Final answer
    x = 208.39

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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.