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Finding the Fourth Proportional to 387.88, 581.44 and 285.60

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Solution

The fourth proportional to 387.88, 581.44 and 285.60 is: 428.12

Step by Step Solution

  1. Step 1: Write the proportion equation
    387.88 : 581.44 = 285.60 : x
  2. Step 2: Convert to fraction form
    387.88/581.44 = 285.60/x
  3. Step 3: Cross multiply
    387.88x = 581.44 × 285.60
  4. Step 4: Simplify right side
    387.88x = 166,059.26
  5. Step 5: Solve for x
    x = 166,059.26/387.88
  6. Step 6: Final answer
    x = 428.12

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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.