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Finding the Fourth Proportional to 97.31, 134.33 and 72.78

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Solution

The fourth proportional to 97.31, 134.33 and 72.78 is: 100.47

Step by Step Solution

  1. Step 1: Write the proportion equation
    97.31 : 134.33 = 72.78 : x
  2. Step 2: Convert to fraction form
    97.31/134.33 = 72.78/x
  3. Step 3: Cross multiply
    97.31x = 134.33 × 72.78
  4. Step 4: Simplify right side
    97.31x = 9,776.54
  5. Step 5: Solve for x
    x = 9,776.54/97.31
  6. Step 6: Final answer
    x = 100.47

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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.