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Finding the Fourth Proportional to 72.91, 109.10 and 61.38

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Solution

The fourth proportional to 72.91, 109.10 and 61.38 is: 91.85

Step by Step Solution

  1. Step 1: Write the proportion equation
    72.91 : 109.10 = 61.38 : x
  2. Step 2: Convert to fraction form
    72.91/109.10 = 61.38/x
  3. Step 3: Cross multiply
    72.91x = 109.10 × 61.38
  4. Step 4: Simplify right side
    72.91x = 6,696.56
  5. Step 5: Solve for x
    x = 6,696.56/72.91
  6. Step 6: Final answer
    x = 91.85

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Why These Related Problems?

These problems maintain the same ratio (1.50) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.