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Finding the Fourth Proportional to 128.50, 177.25 and 103.97

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Solution

The fourth proportional to 128.50, 177.25 and 103.97 is: 143.41

Step by Step Solution

  1. Step 1: Write the proportion equation
    128.50 : 177.25 = 103.97 : x
  2. Step 2: Convert to fraction form
    128.50/177.25 = 103.97/x
  3. Step 3: Cross multiply
    128.50x = 177.25 × 103.97
  4. Step 4: Simplify right side
    128.50x = 18,428.68
  5. Step 5: Solve for x
    x = 18,428.68/128.50
  6. Step 6: Final answer
    x = 143.41

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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.