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Finding the Fourth Proportional to 151.28, 209.11 and 128.09

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Solution

The fourth proportional to 151.28, 209.11 and 128.09 is: 177.06

Step by Step Solution

  1. Step 1: Write the proportion equation
    151.28 : 209.11 = 128.09 : x
  2. Step 2: Convert to fraction form
    151.28/209.11 = 128.09/x
  3. Step 3: Cross multiply
    151.28x = 209.11 × 128.09
  4. Step 4: Simplify right side
    151.28x = 26,784.90
  5. Step 5: Solve for x
    x = 26,784.90/151.28
  6. Step 6: Final answer
    x = 177.06

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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.