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Finding the Fourth Proportional to 428.45, 642.68 and 284.13

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Solution

The fourth proportional to 428.45, 642.68 and 284.13 is: 426.20

Step by Step Solution

  1. Step 1: Write the proportion equation
    428.45 : 642.68 = 284.13 : x
  2. Step 2: Convert to fraction form
    428.45/642.68 = 284.13/x
  3. Step 3: Cross multiply
    428.45x = 642.68 × 284.13
  4. Step 4: Simplify right side
    428.45x = 182,603.25
  5. Step 5: Solve for x
    x = 182,603.25/428.45
  6. Step 6: Final answer
    x = 426.20

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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.