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Finding the Fourth Proportional to 91.21, 136.56 and 68.28

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Solution

The fourth proportional to 91.21, 136.56 and 68.28 is: 102.23

Step by Step Solution

  1. Step 1: Write the proportion equation
    91.21 : 136.56 = 68.28 : x
  2. Step 2: Convert to fraction form
    91.21/136.56 = 68.28/x
  3. Step 3: Cross multiply
    91.21x = 136.56 × 68.28
  4. Step 4: Simplify right side
    91.21x = 9,324.32
  5. Step 5: Solve for x
    x = 9,324.32/91.21
  6. Step 6: Final answer
    x = 102.23

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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.