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Finding the Fourth Proportional to 103.08, 142.20 and 91.56

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Solution

The fourth proportional to 103.08, 142.20 and 91.56 is: 126.31

Step by Step Solution

  1. Step 1: Write the proportion equation
    103.08 : 142.20 = 91.56 : x
  2. Step 2: Convert to fraction form
    103.08/142.20 = 91.56/x
  3. Step 3: Cross multiply
    103.08x = 142.20 × 91.56
  4. Step 4: Simplify right side
    103.08x = 13,019.83
  5. Step 5: Solve for x
    x = 13,019.83/103.08
  6. Step 6: Final answer
    x = 126.31

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Why These Related Problems?

These problems maintain the same ratio (1.38) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.