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Finding the Fourth Proportional to 105.14, 158.32 and 91.78

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Solution

The fourth proportional to 105.14, 158.32 and 91.78 is: 138.20

Step by Step Solution

  1. Step 1: Write the proportion equation
    105.14 : 158.32 = 91.78 : x
  2. Step 2: Convert to fraction form
    105.14/158.32 = 91.78/x
  3. Step 3: Cross multiply
    105.14x = 158.32 × 91.78
  4. Step 4: Simplify right side
    105.14x = 14,530.61
  5. Step 5: Solve for x
    x = 14,530.61/105.14
  6. Step 6: Final answer
    x = 138.20

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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.