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Finding the Fourth Proportional to 86.59, 129.79 and 74.62

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Solution

The fourth proportional to 86.59, 129.79 and 74.62 is: 111.85

Step by Step Solution

  1. Step 1: Write the proportion equation
    86.59 : 129.79 = 74.62 : x
  2. Step 2: Convert to fraction form
    86.59/129.79 = 74.62/x
  3. Step 3: Cross multiply
    86.59x = 129.79 × 74.62
  4. Step 4: Simplify right side
    86.59x = 9,684.93
  5. Step 5: Solve for x
    x = 9,684.93/86.59
  6. Step 6: Final answer
    x = 111.85

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Why These Related Problems?

These problems maintain the same ratio (1.50) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.