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Finding the Fourth Proportional to 412.21, 618.28 and 138.29

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Solution

The fourth proportional to 412.21, 618.28 and 138.29 is: 207.42

Step by Step Solution

  1. Step 1: Write the proportion equation
    412.21 : 618.28 = 138.29 : x
  2. Step 2: Convert to fraction form
    412.21/618.28 = 138.29/x
  3. Step 3: Cross multiply
    412.21x = 618.28 × 138.29
  4. Step 4: Simplify right side
    412.21x = 85,498.50
  5. Step 5: Solve for x
    x = 85,498.50/412.21
  6. Step 6: Final answer
    x = 207.42

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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.