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Finding the Fourth Proportional to 428.84, 642.95 and 284.25

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Solution

The fourth proportional to 428.84, 642.95 and 284.25 is: 426.17

Step by Step Solution

  1. Step 1: Write the proportion equation
    428.84 : 642.95 = 284.25 : x
  2. Step 2: Convert to fraction form
    428.84/642.95 = 284.25/x
  3. Step 3: Cross multiply
    428.84x = 642.95 × 284.25
  4. Step 4: Simplify right side
    428.84x = 182,757.12
  5. Step 5: Solve for x
    x = 182,757.12/428.84
  6. Step 6: Final answer
    x = 426.17

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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.