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Finding the Fourth Proportional to 82.15, 113.07 and 72.91

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Solution

The fourth proportional to 82.15, 113.07 and 72.91 is: 100.35

Step by Step Solution

  1. Step 1: Write the proportion equation
    82.15 : 113.07 = 72.91 : x
  2. Step 2: Convert to fraction form
    82.15/113.07 = 72.91/x
  3. Step 3: Cross multiply
    82.15x = 113.07 × 72.91
  4. Step 4: Simplify right side
    82.15x = 8,243.93
  5. Step 5: Solve for x
    x = 8,243.93/82.15
  6. Step 6: Final answer
    x = 100.35

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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.