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Finding the Fourth Proportional to 101.18, 139.57 and 87.36

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Solution

The fourth proportional to 101.18, 139.57 and 87.36 is: 120.51

Step by Step Solution

  1. Step 1: Write the proportion equation
    101.18 : 139.57 = 87.36 : x
  2. Step 2: Convert to fraction form
    101.18/139.57 = 87.36/x
  3. Step 3: Cross multiply
    101.18x = 139.57 × 87.36
  4. Step 4: Simplify right side
    101.18x = 12,192.42
  5. Step 5: Solve for x
    x = 12,192.42/101.18
  6. Step 6: Final answer
    x = 120.51

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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.