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Finding the Fourth Proportional to 609.20, 912.60 and 392

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Solution

The fourth proportional to 609.20, 912.60 and 392 is: 587.23

Step by Step Solution

  1. Step 1: Write the proportion equation
    609.20 : 912.60 = 392 : x
  2. Step 2: Convert to fraction form
    609.20/912.60 = 392/x
  3. Step 3: Cross multiply
    609.20x = 912.60 × 392
  4. Step 4: Simplify right side
    609.20x = 357,739.20
  5. Step 5: Solve for x
    x = 357,739.20/609.20
  6. Step 6: Final answer
    x = 587.23

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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.