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Finding the Fourth Proportional to 920.92, 1,381.59 and 343.78

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Solution

The fourth proportional to 920.92, 1,381.59 and 343.78 is: 515.75

Step by Step Solution

  1. Step 1: Write the proportion equation
    920.92 : 1,381.59 = 343.78 : x
  2. Step 2: Convert to fraction form
    920.92/1,381.59 = 343.78/x
  3. Step 3: Cross multiply
    920.92x = 1,381.59 × 343.78
  4. Step 4: Simplify right side
    920.92x = 474,963.01
  5. Step 5: Solve for x
    x = 474,963.01/920.92
  6. Step 6: Final answer
    x = 515.75

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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.