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Finding the Fourth Proportional to 403.20, 608.40 and 381.60

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Solution

The fourth proportional to 403.20, 608.40 and 381.60 is: 575.81

Step by Step Solution

  1. Step 1: Write the proportion equation
    403.20 : 608.40 = 381.60 : x
  2. Step 2: Convert to fraction form
    403.20/608.40 = 381.60/x
  3. Step 3: Cross multiply
    403.20x = 608.40 × 381.60
  4. Step 4: Simplify right side
    403.20x = 232,165.44
  5. Step 5: Solve for x
    x = 232,165.44/403.20
  6. Step 6: Final answer
    x = 575.81

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Why These Related Problems?

These problems maintain the same ratio (1.51) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.