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Finding the Fourth Proportional to 428.72, 642.95 and 274.82

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Solution

The fourth proportional to 428.72, 642.95 and 274.82 is: 412.14

Step by Step Solution

  1. Step 1: Write the proportion equation
    428.72 : 642.95 = 274.82 : x
  2. Step 2: Convert to fraction form
    428.72/642.95 = 274.82/x
  3. Step 3: Cross multiply
    428.72x = 642.95 × 274.82
  4. Step 4: Simplify right side
    428.72x = 176,694.14
  5. Step 5: Solve for x
    x = 176,694.14/428.72
  6. Step 6: Final answer
    x = 412.14

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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.