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Finding the Fourth Proportional to 439.20, 605.40 and 345.72

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Solution

The fourth proportional to 439.20, 605.40 and 345.72 is: 476.55

Step by Step Solution

  1. Step 1: Write the proportion equation
    439.20 : 605.40 = 345.72 : x
  2. Step 2: Convert to fraction form
    439.20/605.40 = 345.72/x
  3. Step 3: Cross multiply
    439.20x = 605.40 × 345.72
  4. Step 4: Simplify right side
    439.20x = 209,298.89
  5. Step 5: Solve for x
    x = 209,298.89/439.20
  6. Step 6: Final answer
    x = 476.55

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Why These Related Problems?

These problems maintain the same ratio (1.38) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.