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Finding the Fourth Proportional to 548.80, 821.60 and 431.20

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Solution

The fourth proportional to 548.80, 821.60 and 431.20 is: 645.54

Step by Step Solution

  1. Step 1: Write the proportion equation
    548.80 : 821.60 = 431.20 : x
  2. Step 2: Convert to fraction form
    548.80/821.60 = 431.20/x
  3. Step 3: Cross multiply
    548.80x = 821.60 × 431.20
  4. Step 4: Simplify right side
    548.80x = 354,273.92
  5. Step 5: Solve for x
    x = 354,273.92/548.80
  6. Step 6: Final answer
    x = 645.54

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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.