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Finding the Fourth Proportional to 101.88, 140.78 and 84.60

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Solution

The fourth proportional to 101.88, 140.78 and 84.60 is: 116.90

Step by Step Solution

  1. Step 1: Write the proportion equation
    101.88 : 140.78 = 84.60 : x
  2. Step 2: Convert to fraction form
    101.88/140.78 = 84.60/x
  3. Step 3: Cross multiply
    101.88x = 140.78 × 84.60
  4. Step 4: Simplify right side
    101.88x = 11,909.99
  5. Step 5: Solve for x
    x = 11,909.99/101.88
  6. Step 6: Final answer
    x = 116.90

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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.