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Finding the Fourth Proportional to 137.20, 189.41 and 90.64

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Solution

The fourth proportional to 137.20, 189.41 and 90.64 is: 125.13

Step by Step Solution

  1. Step 1: Write the proportion equation
    137.20 : 189.41 = 90.64 : x
  2. Step 2: Convert to fraction form
    137.20/189.41 = 90.64/x
  3. Step 3: Cross multiply
    137.20x = 189.41 × 90.64
  4. Step 4: Simplify right side
    137.20x = 17,168.12
  5. Step 5: Solve for x
    x = 17,168.12/137.20
  6. Step 6: Final answer
    x = 125.13

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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.