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Finding the Fourth Proportional to 721.50, 1,082.25 and 208.50

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Solution

The fourth proportional to 721.50, 1,082.25 and 208.50 is: 312.75

Step by Step Solution

  1. Step 1: Write the proportion equation
    721.50 : 1,082.25 = 208.50 : x
  2. Step 2: Convert to fraction form
    721.50/1,082.25 = 208.50/x
  3. Step 3: Cross multiply
    721.50x = 1,082.25 × 208.50
  4. Step 4: Simplify right side
    721.50x = 225,649.13
  5. Step 5: Solve for x
    x = 225,649.13/721.50
  6. Step 6: Final answer
    x = 312.75

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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.