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Finding the Fourth Proportional to 72.28, 107.90 and 68.20

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Solution

The fourth proportional to 72.28, 107.90 and 68.20 is: 101.81

Step by Step Solution

  1. Step 1: Write the proportion equation
    72.28 : 107.90 = 68.20 : x
  2. Step 2: Convert to fraction form
    72.28/107.90 = 68.20/x
  3. Step 3: Cross multiply
    72.28x = 107.90 × 68.20
  4. Step 4: Simplify right side
    72.28x = 7,358.78
  5. Step 5: Solve for x
    x = 7,358.78/72.28
  6. Step 6: Final answer
    x = 101.81

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Why These Related Problems?

These problems maintain the same ratio (1.49) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.