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Finding the Fourth Proportional to 128.57, 178.29 and 124.47

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Solution

The fourth proportional to 128.57, 178.29 and 124.47 is: 172.61

Step by Step Solution

  1. Step 1: Write the proportion equation
    128.57 : 178.29 = 124.47 : x
  2. Step 2: Convert to fraction form
    128.57/178.29 = 124.47/x
  3. Step 3: Cross multiply
    128.57x = 178.29 × 124.47
  4. Step 4: Simplify right side
    128.57x = 22,191.76
  5. Step 5: Solve for x
    x = 22,191.76/128.57
  6. Step 6: Final answer
    x = 172.61

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Why These Related Problems?

These problems maintain the same ratio (1.39) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.