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Finding the Fourth Proportional to 207.35, 286.15 and 128.68

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Solution

The fourth proportional to 207.35, 286.15 and 128.68 is: 177.58

Step by Step Solution

  1. Step 1: Write the proportion equation
    207.35 : 286.15 = 128.68 : x
  2. Step 2: Convert to fraction form
    207.35/286.15 = 128.68/x
  3. Step 3: Cross multiply
    207.35x = 286.15 × 128.68
  4. Step 4: Simplify right side
    207.35x = 36,821.78
  5. Step 5: Solve for x
    x = 36,821.78/207.35
  6. Step 6: Final answer
    x = 177.58

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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.