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Finding the Fourth Proportional to 920.72, 1,380.36 and 343.28

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Solution

The fourth proportional to 920.72, 1,380.36 and 343.28 is: 514.65

Step by Step Solution

  1. Step 1: Write the proportion equation
    920.72 : 1,380.36 = 343.28 : x
  2. Step 2: Convert to fraction form
    920.72/1,380.36 = 343.28/x
  3. Step 3: Cross multiply
    920.72x = 1,380.36 × 343.28
  4. Step 4: Simplify right side
    920.72x = 473,849.98
  5. Step 5: Solve for x
    x = 473,849.98/920.72
  6. Step 6: Final answer
    x = 514.65

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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.