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Finding the Fourth Proportional to 279.06, 385.20 and 221.10

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Solution

The fourth proportional to 279.06, 385.20 and 221.10 is: 305.20

Step by Step Solution

  1. Step 1: Write the proportion equation
    279.06 : 385.20 = 221.10 : x
  2. Step 2: Convert to fraction form
    279.06/385.20 = 221.10/x
  3. Step 3: Cross multiply
    279.06x = 385.20 × 221.10
  4. Step 4: Simplify right side
    279.06x = 85,167.72
  5. Step 5: Solve for x
    x = 85,167.72/279.06
  6. Step 6: Final answer
    x = 305.20

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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.