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Finding the Fourth Proportional to 920.28, 1,380 and 342.75

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Solution

The fourth proportional to 920.28, 1,380 and 342.75 is: 513.97

Step by Step Solution

  1. Step 1: Write the proportion equation
    920.28 : 1,380 = 342.75 : x
  2. Step 2: Convert to fraction form
    920.28/1,380 = 342.75/x
  3. Step 3: Cross multiply
    920.28x = 1,380 × 342.75
  4. Step 4: Simplify right side
    920.28x = 472,995
  5. Step 5: Solve for x
    x = 472,995/920.28
  6. Step 6: Final answer
    x = 513.97

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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.