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Finding the Fourth Proportional to 279.45, 385.16 and 209.39

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Solution

The fourth proportional to 279.45, 385.16 and 209.39 is: 288.59

Step by Step Solution

  1. Step 1: Write the proportion equation
    279.45 : 385.16 = 209.39 : x
  2. Step 2: Convert to fraction form
    279.45/385.16 = 209.39/x
  3. Step 3: Cross multiply
    279.45x = 385.16 × 209.39
  4. Step 4: Simplify right side
    279.45x = 80,645.68
  5. Step 5: Solve for x
    x = 80,645.68/279.45
  6. Step 6: Final answer
    x = 288.59

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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.