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Finding the Fourth Proportional to 206.68, 285.20 and 136.80

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Solution

The fourth proportional to 206.68, 285.20 and 136.80 is: 188.77

Step by Step Solution

  1. Step 1: Write the proportion equation
    206.68 : 285.20 = 136.80 : x
  2. Step 2: Convert to fraction form
    206.68/285.20 = 136.80/x
  3. Step 3: Cross multiply
    206.68x = 285.20 × 136.80
  4. Step 4: Simplify right side
    206.68x = 39,015.36
  5. Step 5: Solve for x
    x = 39,015.36/206.68
  6. Step 6: Final answer
    x = 188.77

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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.