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Finding the Fourth Proportional to 343.89, 515.90 and 138.48

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Solution

The fourth proportional to 343.89, 515.90 and 138.48 is: 207.75

Step by Step Solution

  1. Step 1: Write the proportion equation
    343.89 : 515.90 = 138.48 : x
  2. Step 2: Convert to fraction form
    343.89/515.90 = 138.48/x
  3. Step 3: Cross multiply
    343.89x = 515.90 × 138.48
  4. Step 4: Simplify right side
    343.89x = 71,442.18
  5. Step 5: Solve for x
    x = 71,442.18/343.89
  6. Step 6: Final answer
    x = 207.75

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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.