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Finding the Fourth Proportional to 102.81, 154.41 and 91.05

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Solution

The fourth proportional to 102.81, 154.41 and 91.05 is: 136.75

Step by Step Solution

  1. Step 1: Write the proportion equation
    102.81 : 154.41 = 91.05 : x
  2. Step 2: Convert to fraction form
    102.81/154.41 = 91.05/x
  3. Step 3: Cross multiply
    102.81x = 154.41 × 91.05
  4. Step 4: Simplify right side
    102.81x = 14,059.03
  5. Step 5: Solve for x
    x = 14,059.03/102.81
  6. Step 6: Final answer
    x = 136.75

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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.