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Finding the Fourth Proportional to 90.76, 136.60 and 68.05

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Solution

The fourth proportional to 90.76, 136.60 and 68.05 is: 102.42

Step by Step Solution

  1. Step 1: Write the proportion equation
    90.76 : 136.60 = 68.05 : x
  2. Step 2: Convert to fraction form
    90.76/136.60 = 68.05/x
  3. Step 3: Cross multiply
    90.76x = 136.60 × 68.05
  4. Step 4: Simplify right side
    90.76x = 9,295.63
  5. Step 5: Solve for x
    x = 9,295.63/90.76
  6. Step 6: Final answer
    x = 102.42

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Why These Related Problems?

These problems maintain the same ratio (1.51) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.