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Finding the Fourth Proportional to 82.11, 122.71 and 66.91

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Solution

The fourth proportional to 82.11, 122.71 and 66.91 is: 99.99

Step by Step Solution

  1. Step 1: Write the proportion equation
    82.11 : 122.71 = 66.91 : x
  2. Step 2: Convert to fraction form
    82.11/122.71 = 66.91/x
  3. Step 3: Cross multiply
    82.11x = 122.71 × 66.91
  4. Step 4: Simplify right side
    82.11x = 8,210.22
  5. Step 5: Solve for x
    x = 8,210.22/82.11
  6. Step 6: Final answer
    x = 99.99

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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.