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Finding the Fourth Proportional to 85.08, 128.38 and 82.06

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Solution

The fourth proportional to 85.08, 128.38 and 82.06 is: 123.82

Step by Step Solution

  1. Step 1: Write the proportion equation
    85.08 : 128.38 = 82.06 : x
  2. Step 2: Convert to fraction form
    85.08/128.38 = 82.06/x
  3. Step 3: Cross multiply
    85.08x = 128.38 × 82.06
  4. Step 4: Simplify right side
    85.08x = 10,534.86
  5. Step 5: Solve for x
    x = 10,534.86/85.08
  6. Step 6: Final answer
    x = 123.82

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Why These Related Problems?

These problems maintain the same ratio (1.51) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.