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Finding the Fourth Proportional to 387.61, 534.90 and 221.83

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Solution

The fourth proportional to 387.61, 534.90 and 221.83 is: 306.12

Step by Step Solution

  1. Step 1: Write the proportion equation
    387.61 : 534.90 = 221.83 : x
  2. Step 2: Convert to fraction form
    387.61/534.90 = 221.83/x
  3. Step 3: Cross multiply
    387.61x = 534.90 × 221.83
  4. Step 4: Simplify right side
    387.61x = 118,655.61
  5. Step 5: Solve for x
    x = 118,655.61/387.61
  6. Step 6: Final answer
    x = 306.12

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Why These Related Problems?

These problems maintain the same ratio (1.38) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.