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Finding the Fourth Proportional to 148.05, 204.21 and 128.61

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Solution

The fourth proportional to 148.05, 204.21 and 128.61 is: 177.40

Step by Step Solution

  1. Step 1: Write the proportion equation
    148.05 : 204.21 = 128.61 : x
  2. Step 2: Convert to fraction form
    148.05/204.21 = 128.61/x
  3. Step 3: Cross multiply
    148.05x = 204.21 × 128.61
  4. Step 4: Simplify right side
    148.05x = 26,263.45
  5. Step 5: Solve for x
    x = 26,263.45/148.05
  6. Step 6: Final answer
    x = 177.40

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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.