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Finding the Fourth Proportional to 137.09, 189.03 and 87.18

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Solution

The fourth proportional to 137.09, 189.03 and 87.18 is: 120.21

Step by Step Solution

  1. Step 1: Write the proportion equation
    137.09 : 189.03 = 87.18 : x
  2. Step 2: Convert to fraction form
    137.09/189.03 = 87.18/x
  3. Step 3: Cross multiply
    137.09x = 189.03 × 87.18
  4. Step 4: Simplify right side
    137.09x = 16,479.25
  5. Step 5: Solve for x
    x = 16,479.25/137.09
  6. Step 6: Final answer
    x = 120.21

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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.