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Finding the Fourth Proportional to 206.20, 308.90 and 124.80

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Solution

The fourth proportional to 206.20, 308.90 and 124.80 is: 186.96

Step by Step Solution

  1. Step 1: Write the proportion equation
    206.20 : 308.90 = 124.80 : x
  2. Step 2: Convert to fraction form
    206.20/308.90 = 124.80/x
  3. Step 3: Cross multiply
    206.20x = 308.90 × 124.80
  4. Step 4: Simplify right side
    206.20x = 38,550.72
  5. Step 5: Solve for x
    x = 38,550.72/206.20
  6. Step 6: Final answer
    x = 186.96

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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.