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Finding the Fourth Proportional to 878.28, 1,211.90 and 505.32

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Solution

The fourth proportional to 878.28, 1,211.90 and 505.32 is: 697.27

Step by Step Solution

  1. Step 1: Write the proportion equation
    878.28 : 1,211.90 = 505.32 : x
  2. Step 2: Convert to fraction form
    878.28/1,211.90 = 505.32/x
  3. Step 3: Cross multiply
    878.28x = 1,211.90 × 505.32
  4. Step 4: Simplify right side
    878.28x = 612,397.31
  5. Step 5: Solve for x
    x = 612,397.31/878.28
  6. Step 6: Final answer
    x = 697.27

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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.