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Finding the Fourth Proportional to 280.87, 421.11 and 143.73

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Solution

The fourth proportional to 280.87, 421.11 and 143.73 is: 215.50

Step by Step Solution

  1. Step 1: Write the proportion equation
    280.87 : 421.11 = 143.73 : x
  2. Step 2: Convert to fraction form
    280.87/421.11 = 143.73/x
  3. Step 3: Cross multiply
    280.87x = 421.11 × 143.73
  4. Step 4: Simplify right side
    280.87x = 60,526.14
  5. Step 5: Solve for x
    x = 60,526.14/280.87
  6. Step 6: Final answer
    x = 215.50

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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.