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Finding the Fourth Proportional to 206.51, 284.85 and 128.88

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Solution

The fourth proportional to 206.51, 284.85 and 128.88 is: 177.77

Step by Step Solution

  1. Step 1: Write the proportion equation
    206.51 : 284.85 = 128.88 : x
  2. Step 2: Convert to fraction form
    206.51/284.85 = 128.88/x
  3. Step 3: Cross multiply
    206.51x = 284.85 × 128.88
  4. Step 4: Simplify right side
    206.51x = 36,711.47
  5. Step 5: Solve for x
    x = 36,711.47/206.51
  6. Step 6: Final answer
    x = 177.77

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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.