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Finding the Fourth Proportional to 279.03, 385.40 and 209.40

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Solution

The fourth proportional to 279.03, 385.40 and 209.40 is: 289.23

Step by Step Solution

  1. Step 1: Write the proportion equation
    279.03 : 385.40 = 209.40 : x
  2. Step 2: Convert to fraction form
    279.03/385.40 = 209.40/x
  3. Step 3: Cross multiply
    279.03x = 385.40 × 209.40
  4. Step 4: Simplify right side
    279.03x = 80,702.76
  5. Step 5: Solve for x
    x = 80,702.76/279.03
  6. Step 6: Final answer
    x = 289.23

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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.