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Finding the Fourth Proportional to 207.55, 286.33 and 128.81

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Solution

The fourth proportional to 207.55, 286.33 and 128.81 is: 177.70

Step by Step Solution

  1. Step 1: Write the proportion equation
    207.55 : 286.33 = 128.81 : x
  2. Step 2: Convert to fraction form
    207.55/286.33 = 128.81/x
  3. Step 3: Cross multiply
    207.55x = 286.33 × 128.81
  4. Step 4: Simplify right side
    207.55x = 36,882.17
  5. Step 5: Solve for x
    x = 36,882.17/207.55
  6. Step 6: Final answer
    x = 177.70

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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.