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Finding the Fourth Proportional to 343.80, 515.70 and 138.28

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Solution

The fourth proportional to 343.80, 515.70 and 138.28 is: 207.42

Step by Step Solution

  1. Step 1: Write the proportion equation
    343.80 : 515.70 = 138.28 : x
  2. Step 2: Convert to fraction form
    343.80/515.70 = 138.28/x
  3. Step 3: Cross multiply
    343.80x = 515.70 × 138.28
  4. Step 4: Simplify right side
    343.80x = 71,311.00
  5. Step 5: Solve for x
    x = 71,311.00/343.80
  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.