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Finding the Fourth Proportional to 920, 1,379.68 and 342.56

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Solution

The fourth proportional to 920, 1,379.68 and 342.56 is: 513.72

Step by Step Solution

  1. Step 1: Write the proportion equation
    920 : 1,379.68 = 342.56 : x
  2. Step 2: Convert to fraction form
    920/1,379.68 = 342.56/x
  3. Step 3: Cross multiply
    920x = 1,379.68 × 342.56
  4. Step 4: Simplify right side
    920x = 472,623.18
  5. Step 5: Solve for x
    x = 472,623.18/920
  6. Step 6: Final answer
    x = 513.72

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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.