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Finding the Fourth Proportional to 139.78, 209.82 and 114.40

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Solution

The fourth proportional to 139.78, 209.82 and 114.40 is: 171.72

Step by Step Solution

  1. Step 1: Write the proportion equation
    139.78 : 209.82 = 114.40 : x
  2. Step 2: Convert to fraction form
    139.78/209.82 = 114.40/x
  3. Step 3: Cross multiply
    139.78x = 209.82 × 114.40
  4. Step 4: Simplify right side
    139.78x = 24,003.41
  5. Step 5: Solve for x
    x = 24,003.41/139.78
  6. Step 6: Final answer
    x = 171.72

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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.