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Finding the Fourth Proportional to 86.06, 129.56 and 85.70

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Solution

The fourth proportional to 86.06, 129.56 and 85.70 is: 129.02

Step by Step Solution

  1. Step 1: Write the proportion equation
    86.06 : 129.56 = 85.70 : x
  2. Step 2: Convert to fraction form
    86.06/129.56 = 85.70/x
  3. Step 3: Cross multiply
    86.06x = 129.56 × 85.70
  4. Step 4: Simplify right side
    86.06x = 11,103.29
  5. Step 5: Solve for x
    x = 11,103.29/86.06
  6. Step 6: Final answer
    x = 129.02

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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.