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Finding the Fourth Proportional to 129.80, 193.52 and 128.18

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Solution

The fourth proportional to 129.80, 193.52 and 128.18 is: 191.11

Step by Step Solution

  1. Step 1: Write the proportion equation
    129.80 : 193.52 = 128.18 : x
  2. Step 2: Convert to fraction form
    129.80/193.52 = 128.18/x
  3. Step 3: Cross multiply
    129.80x = 193.52 × 128.18
  4. Step 4: Simplify right side
    129.80x = 24,806.20
  5. Step 5: Solve for x
    x = 24,806.20/129.80
  6. Step 6: Final answer
    x = 191.11

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Why These Related Problems?

These problems maintain the same ratio (1.49) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.