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Finding the Fourth Proportional to 101.66, 139.96 and 87.82

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Solution

The fourth proportional to 101.66, 139.96 and 87.82 is: 120.91

Step by Step Solution

  1. Step 1: Write the proportion equation
    101.66 : 139.96 = 87.82 : x
  2. Step 2: Convert to fraction form
    101.66/139.96 = 87.82/x
  3. Step 3: Cross multiply
    101.66x = 139.96 × 87.82
  4. Step 4: Simplify right side
    101.66x = 12,291.05
  5. Step 5: Solve for x
    x = 12,291.05/101.66
  6. Step 6: Final answer
    x = 120.91

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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.