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Finding the Fourth Proportional to 387.31, 581.14 and 143.80

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Solution

The fourth proportional to 387.31, 581.14 and 143.80 is: 215.76

Step by Step Solution

  1. Step 1: Write the proportion equation
    387.31 : 581.14 = 143.80 : x
  2. Step 2: Convert to fraction form
    387.31/581.14 = 143.80/x
  3. Step 3: Cross multiply
    387.31x = 581.14 × 143.80
  4. Step 4: Simplify right side
    387.31x = 83,567.93
  5. Step 5: Solve for x
    x = 83,567.93/387.31
  6. Step 6: Final answer
    x = 215.76

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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.