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Finding the Fourth Proportional to 878.38, 1,212.13 and 505.51

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Solution

The fourth proportional to 878.38, 1,212.13 and 505.51 is: 697.58

Step by Step Solution

  1. Step 1: Write the proportion equation
    878.38 : 1,212.13 = 505.51 : x
  2. Step 2: Convert to fraction form
    878.38/1,212.13 = 505.51/x
  3. Step 3: Cross multiply
    878.38x = 1,212.13 × 505.51
  4. Step 4: Simplify right side
    878.38x = 612,741.44
  5. Step 5: Solve for x
    x = 612,741.44/878.38
  6. Step 6: Final answer
    x = 697.58

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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.