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Finding the Fourth Proportional to 638.69, 878.45 and 555.93

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Solution

The fourth proportional to 638.69, 878.45 and 555.93 is: 764.62

Step by Step Solution

  1. Step 1: Write the proportion equation
    638.69 : 878.45 = 555.93 : x
  2. Step 2: Convert to fraction form
    638.69/878.45 = 555.93/x
  3. Step 3: Cross multiply
    638.69x = 878.45 × 555.93
  4. Step 4: Simplify right side
    638.69x = 488,353.93
  5. Step 5: Solve for x
    x = 488,353.93/638.69
  6. Step 6: Final answer
    x = 764.62

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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.