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Finding the Fourth Proportional to 101.50, 139.75 and 76.89

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Solution

The fourth proportional to 101.50, 139.75 and 76.89 is: 105.87

Step by Step Solution

  1. Step 1: Write the proportion equation
    101.50 : 139.75 = 76.89 : x
  2. Step 2: Convert to fraction form
    101.50/139.75 = 76.89/x
  3. Step 3: Cross multiply
    101.50x = 139.75 × 76.89
  4. Step 4: Simplify right side
    101.50x = 10,745.19
  5. Step 5: Solve for x
    x = 10,745.19/101.50
  6. Step 6: Final answer
    x = 105.87

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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.