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Finding the Fourth Proportional to 420.93, 580.57 and 281.21

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Solution

The fourth proportional to 420.93, 580.57 and 281.21 is: 387.85

Step by Step Solution

  1. Step 1: Write the proportion equation
    420.93 : 580.57 = 281.21 : x
  2. Step 2: Convert to fraction form
    420.93/580.57 = 281.21/x
  3. Step 3: Cross multiply
    420.93x = 580.57 × 281.21
  4. Step 4: Simplify right side
    420.93x = 163,258.48
  5. Step 5: Solve for x
    x = 163,258.48/420.93
  6. Step 6: Final answer
    x = 387.85

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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.