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Finding the Fourth Proportional to 280.20, 386.82 and 217.89

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Solution

The fourth proportional to 280.20, 386.82 and 217.89 is: 300.80

Step by Step Solution

  1. Step 1: Write the proportion equation
    280.20 : 386.82 = 217.89 : x
  2. Step 2: Convert to fraction form
    280.20/386.82 = 217.89/x
  3. Step 3: Cross multiply
    280.20x = 386.82 × 217.89
  4. Step 4: Simplify right side
    280.20x = 84,284.21
  5. Step 5: Solve for x
    x = 84,284.21/280.20
  6. Step 6: Final answer
    x = 300.80

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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.