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Finding the Fourth Proportional to 387.56, 534.88 and 221.80

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Solution

The fourth proportional to 387.56, 534.88 and 221.80 is: 306.11

Step by Step Solution

  1. Step 1: Write the proportion equation
    387.56 : 534.88 = 221.80 : x
  2. Step 2: Convert to fraction form
    387.56/534.88 = 221.80/x
  3. Step 3: Cross multiply
    387.56x = 534.88 × 221.80
  4. Step 4: Simplify right side
    387.56x = 118,636.38
  5. Step 5: Solve for x
    x = 118,636.38/387.56
  6. Step 6: Final answer
    x = 306.11

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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.