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Finding the Fourth Proportional to 387.30, 579.60 and 271.20

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Solution

The fourth proportional to 387.30, 579.60 and 271.20 is: 405.85

Step by Step Solution

  1. Step 1: Write the proportion equation
    387.30 : 579.60 = 271.20 : x
  2. Step 2: Convert to fraction form
    387.30/579.60 = 271.20/x
  3. Step 3: Cross multiply
    387.30x = 579.60 × 271.20
  4. Step 4: Simplify right side
    387.30x = 157,187.52
  5. Step 5: Solve for x
    x = 157,187.52/387.30
  6. Step 6: Final answer
    x = 405.85

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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.