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Finding the Fourth Proportional to 392.20, 589.10 and 345.20

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Solution

The fourth proportional to 392.20, 589.10 and 345.20 is: 518.50

Step by Step Solution

  1. Step 1: Write the proportion equation
    392.20 : 589.10 = 345.20 : x
  2. Step 2: Convert to fraction form
    392.20/589.10 = 345.20/x
  3. Step 3: Cross multiply
    392.20x = 589.10 × 345.20
  4. Step 4: Simplify right side
    392.20x = 203,357.32
  5. Step 5: Solve for x
    x = 203,357.32/392.20
  6. Step 6: Final answer
    x = 518.50

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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.