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Finding the Fourth Proportional to 137.85, 206.75 and 68.45

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Solution

The fourth proportional to 137.85, 206.75 and 68.45 is: 102.65

Step by Step Solution

  1. Step 1: Write the proportion equation
    137.85 : 206.75 = 68.45 : x
  2. Step 2: Convert to fraction form
    137.85/206.75 = 68.45/x
  3. Step 3: Cross multiply
    137.85x = 206.75 × 68.45
  4. Step 4: Simplify right side
    137.85x = 14,151.17
  5. Step 5: Solve for x
    x = 14,151.17/137.85
  6. Step 6: Final answer
    x = 102.65

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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.