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Finding the Fourth Proportional to 343.40, 515.20 and 138.12

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Solution

The fourth proportional to 343.40, 515.20 and 138.12 is: 207.22

Step by Step Solution

  1. Step 1: Write the proportion equation
    343.40 : 515.20 = 138.12 : x
  2. Step 2: Convert to fraction form
    343.40/515.20 = 138.12/x
  3. Step 3: Cross multiply
    343.40x = 515.20 × 138.12
  4. Step 4: Simplify right side
    343.40x = 71,159.42
  5. Step 5: Solve for x
    x = 71,159.42/343.40
  6. Step 6: Final answer
    x = 207.22

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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.