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Finding the Fourth Proportional to 128.71, 177.60 and 109.27

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Solution

The fourth proportional to 128.71, 177.60 and 109.27 is: 150.78

Step by Step Solution

  1. Step 1: Write the proportion equation
    128.71 : 177.60 = 109.27 : x
  2. Step 2: Convert to fraction form
    128.71/177.60 = 109.27/x
  3. Step 3: Cross multiply
    128.71x = 177.60 × 109.27
  4. Step 4: Simplify right side
    128.71x = 19,406.35
  5. Step 5: Solve for x
    x = 19,406.35/128.71
  6. Step 6: Final answer
    x = 150.78

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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.