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Finding the Fourth Proportional to 129.33, 193.66 and 77.90

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Solution

The fourth proportional to 129.33, 193.66 and 77.90 is: 116.64

Step by Step Solution

  1. Step 1: Write the proportion equation
    129.33 : 193.66 = 77.90 : x
  2. Step 2: Convert to fraction form
    129.33/193.66 = 77.90/x
  3. Step 3: Cross multiply
    129.33x = 193.66 × 77.90
  4. Step 4: Simplify right side
    129.33x = 15,084.95
  5. Step 5: Solve for x
    x = 15,084.95/129.33
  6. Step 6: Final answer
    x = 116.64

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Why These Related Problems?

These problems maintain the same ratio (1.50) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.