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Finding the Fourth Proportional to 420.64, 580.38 and 281

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Solution

The fourth proportional to 420.64, 580.38 and 281 is: 387.71

Step by Step Solution

  1. Step 1: Write the proportion equation
    420.64 : 580.38 = 281 : x
  2. Step 2: Convert to fraction form
    420.64/580.38 = 281/x
  3. Step 3: Cross multiply
    420.64x = 580.38 × 281
  4. Step 4: Simplify right side
    420.64x = 163,086.78
  5. Step 5: Solve for x
    x = 163,086.78/420.64
  6. Step 6: Final answer
    x = 387.71

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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.