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Finding the Fourth Proportional to 279.56, 385.80 and 209.64

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Solution

The fourth proportional to 279.56, 385.80 and 209.64 is: 289.31

Step by Step Solution

  1. Step 1: Write the proportion equation
    279.56 : 385.80 = 209.64 : x
  2. Step 2: Convert to fraction form
    279.56/385.80 = 209.64/x
  3. Step 3: Cross multiply
    279.56x = 385.80 × 209.64
  4. Step 4: Simplify right side
    279.56x = 80,879.11
  5. Step 5: Solve for x
    x = 80,879.11/279.56
  6. Step 6: Final answer
    x = 289.31

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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.