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Finding the Fourth Proportional to 387.20, 580.62 and 143.66

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Solution

The fourth proportional to 387.20, 580.62 and 143.66 is: 215.42

Step by Step Solution

  1. Step 1: Write the proportion equation
    387.20 : 580.62 = 143.66 : x
  2. Step 2: Convert to fraction form
    387.20/580.62 = 143.66/x
  3. Step 3: Cross multiply
    387.20x = 580.62 × 143.66
  4. Step 4: Simplify right side
    387.20x = 83,411.87
  5. Step 5: Solve for x
    x = 83,411.87/387.20
  6. Step 6: Final answer
    x = 215.42

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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.