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Finding the Fourth Proportional to 72.75, 100.31 and 58.91

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Solution

The fourth proportional to 72.75, 100.31 and 58.91 is: 81.22

Step by Step Solution

  1. Step 1: Write the proportion equation
    72.75 : 100.31 = 58.91 : x
  2. Step 2: Convert to fraction form
    72.75/100.31 = 58.91/x
  3. Step 3: Cross multiply
    72.75x = 100.31 × 58.91
  4. Step 4: Simplify right side
    72.75x = 5,908.47
  5. Step 5: Solve for x
    x = 5,908.47/72.75
  6. Step 6: Final answer
    x = 81.22

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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.