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Finding the Fourth Proportional to 72.78, 108.28 and 68.46

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Solution

The fourth proportional to 72.78, 108.28 and 68.46 is: 101.85

Step by Step Solution

  1. Step 1: Write the proportion equation
    72.78 : 108.28 = 68.46 : x
  2. Step 2: Convert to fraction form
    72.78/108.28 = 68.46/x
  3. Step 3: Cross multiply
    72.78x = 108.28 × 68.46
  4. Step 4: Simplify right side
    72.78x = 7,412.68
  5. Step 5: Solve for x
    x = 7,412.68/72.78
  6. Step 6: Final answer
    x = 101.85

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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.