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Finding the Fourth Proportional to 279.36, 385.56 and 221.58

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Solution

The fourth proportional to 279.36, 385.56 and 221.58 is: 305.81

Step by Step Solution

  1. Step 1: Write the proportion equation
    279.36 : 385.56 = 221.58 : x
  2. Step 2: Convert to fraction form
    279.36/385.56 = 221.58/x
  3. Step 3: Cross multiply
    279.36x = 385.56 × 221.58
  4. Step 4: Simplify right side
    279.36x = 85,432.38
  5. Step 5: Solve for x
    x = 85,432.38/279.36
  6. Step 6: Final answer
    x = 305.81

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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.