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Finding the Fourth Proportional to 457.20, 685.20 and 405.60

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Solution

The fourth proportional to 457.20, 685.20 and 405.60 is: 607.87

Step by Step Solution

  1. Step 1: Write the proportion equation
    457.20 : 685.20 = 405.60 : x
  2. Step 2: Convert to fraction form
    457.20/685.20 = 405.60/x
  3. Step 3: Cross multiply
    457.20x = 685.20 × 405.60
  4. Step 4: Simplify right side
    457.20x = 277,917.12
  5. Step 5: Solve for x
    x = 277,917.12/457.20
  6. Step 6: Final answer
    x = 607.87

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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.