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Finding the Fourth Proportional to 920.20, 1,380.30 and 407.08

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Solution

The fourth proportional to 920.20, 1,380.30 and 407.08 is: 610.62

Step by Step Solution

  1. Step 1: Write the proportion equation
    920.20 : 1,380.30 = 407.08 : x
  2. Step 2: Convert to fraction form
    920.20/1,380.30 = 407.08/x
  3. Step 3: Cross multiply
    920.20x = 1,380.30 × 407.08
  4. Step 4: Simplify right side
    920.20x = 561,892.52
  5. Step 5: Solve for x
    x = 561,892.52/920.20
  6. Step 6: Final answer
    x = 610.62

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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.