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Finding the Fourth Proportional to 101.43, 139.69 and 87.60

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Solution

The fourth proportional to 101.43, 139.69 and 87.60 is: 120.65

Step by Step Solution

  1. Step 1: Write the proportion equation
    101.43 : 139.69 = 87.60 : x
  2. Step 2: Convert to fraction form
    101.43/139.69 = 87.60/x
  3. Step 3: Cross multiply
    101.43x = 139.69 × 87.60
  4. Step 4: Simplify right side
    101.43x = 12,237.19
  5. Step 5: Solve for x
    x = 12,237.19/101.43
  6. Step 6: Final answer
    x = 120.65

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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.