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Finding the Fourth Proportional to 101.81, 140.39 and 78.50

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Solution

The fourth proportional to 101.81, 140.39 and 78.50 is: 108.24

Step by Step Solution

  1. Step 1: Write the proportion equation
    101.81 : 140.39 = 78.50 : x
  2. Step 2: Convert to fraction form
    101.81/140.39 = 78.50/x
  3. Step 3: Cross multiply
    101.81x = 140.39 × 78.50
  4. Step 4: Simplify right side
    101.81x = 11,019.52
  5. Step 5: Solve for x
    x = 11,019.52/101.81
  6. Step 6: Final answer
    x = 108.24

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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.