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Finding the Fourth Proportional to 279.29, 418.40 and 221.21

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Solution

The fourth proportional to 279.29, 418.40 and 221.21 is: 331.39

Step by Step Solution

  1. Step 1: Write the proportion equation
    279.29 : 418.40 = 221.21 : x
  2. Step 2: Convert to fraction form
    279.29/418.40 = 221.21/x
  3. Step 3: Cross multiply
    279.29x = 418.40 × 221.21
  4. Step 4: Simplify right side
    279.29x = 92,551.07
  5. Step 5: Solve for x
    x = 92,551.07/279.29
  6. Step 6: Final answer
    x = 331.39

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Why These Related Problems?

These problems maintain the same ratio (1.50) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.