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Finding the Fourth Proportional to 871.20, 1,200.08 and 684

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Solution

The fourth proportional to 871.20, 1,200.08 and 684 is: 942.21

Step by Step Solution

  1. Step 1: Write the proportion equation
    871.20 : 1,200.08 = 684 : x
  2. Step 2: Convert to fraction form
    871.20/1,200.08 = 684/x
  3. Step 3: Cross multiply
    871.20x = 1,200.08 × 684
  4. Step 4: Simplify right side
    871.20x = 820,854.72
  5. Step 5: Solve for x
    x = 820,854.72/871.20
  6. Step 6: Final answer
    x = 942.21

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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.