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Finding the Fourth Proportional to 101.15, 139.65 and 87.37

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Solution

The fourth proportional to 101.15, 139.65 and 87.37 is: 120.62

Step by Step Solution

  1. Step 1: Write the proportion equation
    101.15 : 139.65 = 87.37 : x
  2. Step 2: Convert to fraction form
    101.15/139.65 = 87.37/x
  3. Step 3: Cross multiply
    101.15x = 139.65 × 87.37
  4. Step 4: Simplify right side
    101.15x = 12,200.59
  5. Step 5: Solve for x
    x = 12,200.59/101.15
  6. Step 6: Final answer
    x = 120.62

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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.