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Finding the Fourth Proportional to 343.68, 515.16 and 138.20

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Solution

The fourth proportional to 343.68, 515.16 and 138.20 is: 207.16

Step by Step Solution

  1. Step 1: Write the proportion equation
    343.68 : 515.16 = 138.20 : x
  2. Step 2: Convert to fraction form
    343.68/515.16 = 138.20/x
  3. Step 3: Cross multiply
    343.68x = 515.16 × 138.20
  4. Step 4: Simplify right side
    343.68x = 71,195.11
  5. Step 5: Solve for x
    x = 71,195.11/343.68
  6. Step 6: Final answer
    x = 207.16

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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.