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Finding the Fourth Proportional to 279.87, 385.76 and 221.55

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Solution

The fourth proportional to 279.87, 385.76 and 221.55 is: 305.37

Step by Step Solution

  1. Step 1: Write the proportion equation
    279.87 : 385.76 = 221.55 : x
  2. Step 2: Convert to fraction form
    279.87/385.76 = 221.55/x
  3. Step 3: Cross multiply
    279.87x = 385.76 × 221.55
  4. Step 4: Simplify right side
    279.87x = 85,464.02
  5. Step 5: Solve for x
    x = 85,464.02/279.87
  6. Step 6: Final answer
    x = 305.37

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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.