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Finding the Fourth Proportional to 878.71, 1,212.34 and 505.55

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Solution

The fourth proportional to 878.71, 1,212.34 and 505.55 is: 697.50

Step by Step Solution

  1. Step 1: Write the proportion equation
    878.71 : 1,212.34 = 505.55 : x
  2. Step 2: Convert to fraction form
    878.71/1,212.34 = 505.55/x
  3. Step 3: Cross multiply
    878.71x = 1,212.34 × 505.55
  4. Step 4: Simplify right side
    878.71x = 612,898.49
  5. Step 5: Solve for x
    x = 612,898.49/878.71
  6. Step 6: Final answer
    x = 697.50

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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.