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Finding the Fourth Proportional to 291.87, 402.12 and 221.76

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Solution

The fourth proportional to 291.87, 402.12 and 221.76 is: 305.53

Step by Step Solution

  1. Step 1: Write the proportion equation
    291.87 : 402.12 = 221.76 : x
  2. Step 2: Convert to fraction form
    291.87/402.12 = 221.76/x
  3. Step 3: Cross multiply
    291.87x = 402.12 × 221.76
  4. Step 4: Simplify right side
    291.87x = 89,174.13
  5. Step 5: Solve for x
    x = 89,174.13/291.87
  6. Step 6: Final answer
    x = 305.53

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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.