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Finding the Fourth Proportional to 148.80, 205.20 and 129.12

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Solution

The fourth proportional to 148.80, 205.20 and 129.12 is: 178.06

Step by Step Solution

  1. Step 1: Write the proportion equation
    148.80 : 205.20 = 129.12 : x
  2. Step 2: Convert to fraction form
    148.80/205.20 = 129.12/x
  3. Step 3: Cross multiply
    148.80x = 205.20 × 129.12
  4. Step 4: Simplify right side
    148.80x = 26,495.42
  5. Step 5: Solve for x
    x = 26,495.42/148.80
  6. Step 6: Final answer
    x = 178.06

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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.