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Finding the Fourth Proportional to 128.59, 177.21 and 102.28

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Solution

The fourth proportional to 128.59, 177.21 and 102.28 is: 140.95

Step by Step Solution

  1. Step 1: Write the proportion equation
    128.59 : 177.21 = 102.28 : x
  2. Step 2: Convert to fraction form
    128.59/177.21 = 102.28/x
  3. Step 3: Cross multiply
    128.59x = 177.21 × 102.28
  4. Step 4: Simplify right side
    128.59x = 18,125.04
  5. Step 5: Solve for x
    x = 18,125.04/128.59
  6. Step 6: Final answer
    x = 140.95

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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.