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Finding the Fourth Proportional to 137.43, 205.78 and 105.39

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Solution

The fourth proportional to 137.43, 205.78 and 105.39 is: 157.80

Step by Step Solution

  1. Step 1: Write the proportion equation
    137.43 : 205.78 = 105.39 : x
  2. Step 2: Convert to fraction form
    137.43/205.78 = 105.39/x
  3. Step 3: Cross multiply
    137.43x = 205.78 × 105.39
  4. Step 4: Simplify right side
    137.43x = 21,685.86
  5. Step 5: Solve for x
    x = 21,685.86/137.43
  6. Step 6: Final answer
    x = 157.80

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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.