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Finding the Fourth Proportional to 127.80, 191.70 and 113.85

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Solution

The fourth proportional to 127.80, 191.70 and 113.85 is: 170.78

Step by Step Solution

  1. Step 1: Write the proportion equation
    127.80 : 191.70 = 113.85 : x
  2. Step 2: Convert to fraction form
    127.80/191.70 = 113.85/x
  3. Step 3: Cross multiply
    127.80x = 191.70 × 113.85
  4. Step 4: Simplify right side
    127.80x = 21,825.05
  5. Step 5: Solve for x
    x = 21,825.05/127.80
  6. Step 6: Final answer
    x = 170.78

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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.