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Finding the Fourth Proportional to 180.78, 271.38 and 99.78

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Solution

The fourth proportional to 180.78, 271.38 and 99.78 is: 149.79

Step by Step Solution

  1. Step 1: Write the proportion equation
    180.78 : 271.38 = 99.78 : x
  2. Step 2: Convert to fraction form
    180.78/271.38 = 99.78/x
  3. Step 3: Cross multiply
    180.78x = 271.38 × 99.78
  4. Step 4: Simplify right side
    180.78x = 27,078.30
  5. Step 5: Solve for x
    x = 27,078.30/180.78
  6. Step 6: Final answer
    x = 149.79

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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.