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Finding the Fourth Proportional to 280.72, 420.67 and 203.85

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Solution

The fourth proportional to 280.72, 420.67 and 203.85 is: 305.47

Step by Step Solution

  1. Step 1: Write the proportion equation
    280.72 : 420.67 = 203.85 : x
  2. Step 2: Convert to fraction form
    280.72/420.67 = 203.85/x
  3. Step 3: Cross multiply
    280.72x = 420.67 × 203.85
  4. Step 4: Simplify right side
    280.72x = 85,750.46
  5. Step 5: Solve for x
    x = 85,750.46/280.72
  6. Step 6: Final answer
    x = 305.47

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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.