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Finding the Fourth Proportional to 721.92, 1,082.78 and 208.92

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Solution

The fourth proportional to 721.92, 1,082.78 and 208.92 is: 313.35

Step by Step Solution

  1. Step 1: Write the proportion equation
    721.92 : 1,082.78 = 208.92 : x
  2. Step 2: Convert to fraction form
    721.92/1,082.78 = 208.92/x
  3. Step 3: Cross multiply
    721.92x = 1,082.78 × 208.92
  4. Step 4: Simplify right side
    721.92x = 226,214.40
  5. Step 5: Solve for x
    x = 226,214.40/721.92
  6. Step 6: Final answer
    x = 313.35

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Why These Related Problems?

These problems maintain the same ratio (1.50) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.