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Finding the Fourth Proportional to 137.88, 206.76 and 105.72

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Solution

The fourth proportional to 137.88, 206.76 and 105.72 is: 158.53

Step by Step Solution

  1. Step 1: Write the proportion equation
    137.88 : 206.76 = 105.72 : x
  2. Step 2: Convert to fraction form
    137.88/206.76 = 105.72/x
  3. Step 3: Cross multiply
    137.88x = 206.76 × 105.72
  4. Step 4: Simplify right side
    137.88x = 21,858.67
  5. Step 5: Solve for x
    x = 21,858.67/137.88
  6. Step 6: Final answer
    x = 158.53

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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.