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Finding the Fourth Proportional to 206.50, 284.86 and 128.74

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Solution

The fourth proportional to 206.50, 284.86 and 128.74 is: 177.59

Step by Step Solution

  1. Step 1: Write the proportion equation
    206.50 : 284.86 = 128.74 : x
  2. Step 2: Convert to fraction form
    206.50/284.86 = 128.74/x
  3. Step 3: Cross multiply
    206.50x = 284.86 × 128.74
  4. Step 4: Simplify right side
    206.50x = 36,672.88
  5. Step 5: Solve for x
    x = 36,672.88/206.50
  6. Step 6: Final answer
    x = 177.59

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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.