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Finding the Fourth Proportional to 279.86, 385.97 and 221.54

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Solution

The fourth proportional to 279.86, 385.97 and 221.54 is: 305.53

Step by Step Solution

  1. Step 1: Write the proportion equation
    279.86 : 385.97 = 221.54 : x
  2. Step 2: Convert to fraction form
    279.86/385.97 = 221.54/x
  3. Step 3: Cross multiply
    279.86x = 385.97 × 221.54
  4. Step 4: Simplify right side
    279.86x = 85,504.76
  5. Step 5: Solve for x
    x = 85,504.76/279.86
  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.