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Finding the Fourth Proportional to 127.90, 191.78 and 54.75

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Solution

The fourth proportional to 127.90, 191.78 and 54.75 is: 82.10

Step by Step Solution

  1. Step 1: Write the proportion equation
    127.90 : 191.78 = 54.75 : x
  2. Step 2: Convert to fraction form
    127.90/191.78 = 54.75/x
  3. Step 3: Cross multiply
    127.90x = 191.78 × 54.75
  4. Step 4: Simplify right side
    127.90x = 10,499.96
  5. Step 5: Solve for x
    x = 10,499.96/127.90
  6. Step 6: Final answer
    x = 82.10

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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.