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Finding the Fourth Proportional to 721.69, 1,082.71 and 208.69

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Solution

The fourth proportional to 721.69, 1,082.71 and 208.69 is: 313.08

Step by Step Solution

  1. Step 1: Write the proportion equation
    721.69 : 1,082.71 = 208.69 : x
  2. Step 2: Convert to fraction form
    721.69/1,082.71 = 208.69/x
  3. Step 3: Cross multiply
    721.69x = 1,082.71 × 208.69
  4. Step 4: Simplify right side
    721.69x = 225,948.30
  5. Step 5: Solve for x
    x = 225,948.30/721.69
  6. Step 6: Final answer
    x = 313.08

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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.