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Finding the Fourth Proportional to 127.89, 191.49 and 100.78

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Solution

The fourth proportional to 127.89, 191.49 and 100.78 is: 150.90

Step by Step Solution

  1. Step 1: Write the proportion equation
    127.89 : 191.49 = 100.78 : x
  2. Step 2: Convert to fraction form
    127.89/191.49 = 100.78/x
  3. Step 3: Cross multiply
    127.89x = 191.49 × 100.78
  4. Step 4: Simplify right side
    127.89x = 19,298.36
  5. Step 5: Solve for x
    x = 19,298.36/127.89
  6. Step 6: Final answer
    x = 150.90

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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.