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Finding the Fourth Proportional to 636, 878.40 and 428.64

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Solution

The fourth proportional to 636, 878.40 and 428.64 is: 592.01

Step by Step Solution

  1. Step 1: Write the proportion equation
    636 : 878.40 = 428.64 : x
  2. Step 2: Convert to fraction form
    636/878.40 = 428.64/x
  3. Step 3: Cross multiply
    636x = 878.40 × 428.64
  4. Step 4: Simplify right side
    636x = 376,517.38
  5. Step 5: Solve for x
    x = 376,517.38/636
  6. Step 6: Final answer
    x = 592.01

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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.