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Finding the Fourth Proportional to 420.63, 580.35 and 280.77

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Solution

The fourth proportional to 420.63, 580.35 and 280.77 is: 387.38

Step by Step Solution

  1. Step 1: Write the proportion equation
    420.63 : 580.35 = 280.77 : x
  2. Step 2: Convert to fraction form
    420.63/580.35 = 280.77/x
  3. Step 3: Cross multiply
    420.63x = 580.35 × 280.77
  4. Step 4: Simplify right side
    420.63x = 162,944.87
  5. Step 5: Solve for x
    x = 162,944.87/420.63
  6. Step 6: Final answer
    x = 387.38

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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.