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Finding the Fourth Proportional to 206.40, 284.52 and 128.64

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Solution

The fourth proportional to 206.40, 284.52 and 128.64 is: 177.33

Step by Step Solution

  1. Step 1: Write the proportion equation
    206.40 : 284.52 = 128.64 : x
  2. Step 2: Convert to fraction form
    206.40/284.52 = 128.64/x
  3. Step 3: Cross multiply
    206.40x = 284.52 × 128.64
  4. Step 4: Simplify right side
    206.40x = 36,600.65
  5. Step 5: Solve for x
    x = 36,600.65/206.40
  6. Step 6: Final answer
    x = 177.33

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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.