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Finding the Fourth Proportional to 101.79, 140.49 and 85.39

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Solution

The fourth proportional to 101.79, 140.49 and 85.39 is: 117.85

Step by Step Solution

  1. Step 1: Write the proportion equation
    101.79 : 140.49 = 85.39 : x
  2. Step 2: Convert to fraction form
    101.79/140.49 = 85.39/x
  3. Step 3: Cross multiply
    101.79x = 140.49 × 85.39
  4. Step 4: Simplify right side
    101.79x = 11,995.74
  5. Step 5: Solve for x
    x = 11,995.74/101.79
  6. Step 6: Final answer
    x = 117.85

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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.