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Finding the Fourth Proportional to 82.62, 123.08 and 81

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Solution

The fourth proportional to 82.62, 123.08 and 81 is: 120.66

Step by Step Solution

  1. Step 1: Write the proportion equation
    82.62 : 123.08 = 81 : x
  2. Step 2: Convert to fraction form
    82.62/123.08 = 81/x
  3. Step 3: Cross multiply
    82.62x = 123.08 × 81
  4. Step 4: Simplify right side
    82.62x = 9,969.08
  5. Step 5: Solve for x
    x = 9,969.08/82.62
  6. Step 6: Final answer
    x = 120.66

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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.